Well, I finally got this all setup. One thing to point out for the few of you that will do this: if you're going to port a mobile number over to o2 prepaid then make sure this is done before you activate myeuropeextra as you lose it when the number port occurs and it takes almost a week for o2 to sort it out!
Anyway, now I'm operational I've tested most aspects of this setup on the following networks/countries and it works perfectly - calls to the returncall trigger number are not charged as well:
Belgium: Proximus (returncall topup shortcode works too!) - Base works fine as well but Mobistar has occasional caller ID & authorisation issues
Germany: T-mobile, o2
Netherlands: KPN Mobile
(I'm particularly glad the phone works fine on another network apart from o2 in Germany as I find their coverage to be terrible in some places!)
Caller ID works perfectly and calls received from anywhere (NOT just the EU) are not charged for. SMS is charged at the 25p rate but I've been using SMSbug on my other data phone for any SMS I send. The one thing I've learnt using o2 is they don't support delivery reports on SMS in the standard way which is a small disadvantage to me making the web method even better
The other small disadvantage is o2 prepaid doesn't support call waiting so especially when using this in combo with returncall it's best to completely turn off the voicemail in my opinion. Now this week I'm going to see if the inclusive GPRS browsing allowance of 5MB (I think this is included for the 1st month) also works abroad.
For the topups I've bought 2x £20 topups from sellers on ebay for £14 each as per a suggestion before. I paid via Paypal and had the voucher codes within a couple of hours. I was then able to call the standard topup number (for free) and apply the £20 credit immediately. To further reduce the costs I'm going to signup for a thing called o2 rewards which I think gives 10% extra credit for free in 3 months time
Finally, for outgoing calls, as per a previous suggestion I've also tried using voipcheap's geographical UK callthru number in conjunction with returncall to make calls to places returncall charges more than the 2p/min UK rate for. I've also tried setting up the Caller ID as a callthru number on my pbxes setup then by calling my UK voip number I get a dialtone and can once again access any of my other voip providers for the same 2p/min. This also works and if I have a particularly long call to make I will do this but for most of the time the returncall rate is perfectly acceptable. As mentioned before there is also the possibility of using SMS trigger callbacks for any moments returncall isn't playing ball but as it seems to work fine (for the moment) I've yet to test this.
Overall I'm very pleased with this new setup! It's much better than using the IoM sim or UM as I've done in the past and for me the best bit is it seems to be super reliable. Hopefully it will stay this way!
PS: For anybody with a UK address you can get o2 sims for free at the moment via the following link:
http://freesimo2.o2.co.uk/
EDIT: GPRS usage is not inclusive and is actually super expensive!
