Okay, according to the first item of the English FAQ the data SIM works only in 15 countries, but the first item of the German FAQ says:
Beyond that why does the link on the data bundle page say "Voice tariffs for United Mobile Data Bundle"?
And if those "Voice tariffs for United Mobile Data Bundle" do not apply for the data SIM and further also do not correspond to the +423-tariff (allthough the document's heading "+423 rate plan" suggest that), what is that rate plan for???

Is there no one at UM to verify their webmaster's work? Apart from this contradictory information the German FAQ need some grammatical correction.

EDIT: All the issues were clearified in the meantime. The English FAQ were amended, accordingly the data SIM actually works in 60 countries for data and voice. Further the mentioned PDF document was wrongly designated ("+423 rate plan") and says "rate plan UM data SIM card" already since noon.

There's also a setup fee of € 0.39 for each connection and 100KB increments billing... :(

I don't like the connect fee either.

ICQ SIM sounds better and better @ €1.17/MB with a daily fee of €0.39. Their voice rates are better too. The only issue is the granularity, at 333KB, but it's still ok for checking your email several times a day.

some news from teltarif.ch
 

just minutes ago, an article about the new prepaid data bundle of UM appeared on www.teltarif.ch. No real news but it clarifies some point of the offer.

Existing coustomers will be able to switch to the new data offer within the next weeks. The data-tariff is regarding this article definately NOT the same than UM +423. The data-sim will only register to the 60 networks that have data-roaming agreement. That might be the reason why the voice tariff is slightly higher.

They have mentioned twice that if you move over to the data-tariff, only will have coverage within the 60 data-roaming countries.

In my opinion the ICQ-SIM tariff is still the better choice with a daily setup fee instead of a session setup fee. Beside that I think this offer might not last too long with this high prices. Weeks ago they would had the best prices for data. Just recently three austria published their new data-roaming prices and they offer 0.28 Euro per MB in Switzerland (swisscom) and about the same for germany (e-plus and vodafone D2). You might argue that this are contract prices and not prepaid prices but that are the best rates I know at the moment...

BK

United mobile got a cash infusion according to this quote from RCR Wireless News "United Mobile: Accel Partners and Grazia Equity invested $15 million into United Mobile, a low-cost roaming mobile operator. The Swiss company offers international travelers prepaid SIM cards that provide voice and data services at low rates worldwide." Looks like they invested it in improving their data services.
I probably would lean towards the new data offer because it covers Caribbean and North America, even though it is at higher rates than ICQ. Agree the ICQ data rates are better, but I don't travel enough to Europe to make that worthwhile to me. Agree on comment the new data offer sounds good for light use like checking email. I'm thinking of just getting the sim card and adding my own data card. Wonder if they will send out an email encouraging people to switch over like they did to get people to go from UM to UM+ service(the TelTarif article sounds like they might). A free sim card would definitely attract my interest.

Got this email today

United Mobile has no longer only worldwide attractive voice rates: now we can also offer low-rate mobile internet services (from only € 0,99/MB). We have special offers now available in our online shop
Mobile Data Bundle: Data SIM + Data Stick for only € 99,-
Mobile Data SIM only € 19,90 (incl. € 10,- call credit) promotion offer instead of € 29,90 regular price
Data-Services for existing Customers
During month of May we will be able to make Data Services available for existing customers on +423 upon request. We will inform about availability and conditions shortly.
Price cuts in different tariff zones
As of May all of our customers can profit from price cuts in our voice rate plans. For example outgoing calls at 59 ct/minute will be only at 39 ct/minute (applying for instance for calls from Zone 1 in to Area 2).
For further information, please visit our website or contact our Customer Service.
Best regards,
United Mobile Team
Is a special device needed to use the new Data SIM?

You can use the Data SIM literally in any device that supports data transmission. For mobile internet usage in laptops we recommend our mobile data stick which is part of the mobile data bundle.

I might do this. Particularly if I can port the +423 to ICQ.

I carry a data enabled PDA but would love the option to tether it. The data sim would murder me with push e-mail or pulling e-mail on a semi-regular basis to my PDA.

The ICQ SIM might make more sense. As noted in another post, I'm also eying Vodafone's new offering which is 12 euros a day for unlimited in the EU roaming. I still haven't seen the terms and conditions so I don't know things like whether it is a new 12 Euros each time I cross a border. Imagine sitting on a train and going through four countries!

I'm wondering if we want to expand our data roaming section and possibly come up with some sample transactions tied to a common currency so that we can compare like things. I know two users are the same, but we can probably come up with some benchmarks.

@stu
The UM data SIM and the ICQ SIM are not the same! They differ in roaming countries, pricing and especially in the session-setup-fee.
Whereas ICQ customers pay only € 0,39 for each day of data usage, UM data customers are charged € 0,39 for each datasession. And since datasessions are regularly interrupted (e.g. if you're out of coverage, if handovers fail or if a cell is overloaded) you must reckon with extra costs for the session-setup-fees of the UM data SIM.
Anyway as +423 customer you'll only be able to switch to the UM data tariff and not to the ICQ tariff. Also keep in mind, that voice tariffs of the UM data SIM are worse than the +423 SIM in many places - so you should exactly compare the prices for the countries you regularly travel to before you switch.

Roaming of the +423 SIM card has been limited in Germany. Allthough I was able to register on all four German networks on May 3rd, today I determined, that my +423 SIM is being rejected by T-Mobile Germany and O2 Germany, so only Vodafone and eplus work.
I suspect this limitation to be caused by some HLR-modification, that will enable +423 customers switching to the new data tariff soon.

First of all it looks like the new data UM plan is considerably more expensive in some countries like France, Ireland, Luxembourg (1.49 EUR/100 kB versus 0.99EUR for Germany, Italy,...). I can't remember how this works: do we pay VAT on top of it like with skype for example or are this the "real" rates?

Anyway it doesn't look so good: not even all EU countries are covered and I am really curios to see if more exotic destinations like Turkey, South Korea or even Japan or US work at all.

Also I don't like the connection fee but on the other hand this might be a price United Mobile really has to pay (not precisely that amount but something proportional).

I don't have any news but the anounced conversion of old UM sims to data doesn't seem to go anywhere (maybe they just have some delays).

I am really looking forward for the time when I'll be able to do some very very light surfing and email checking in roaming without breaking the bank.