Raketu
 

I was wondering if anyone has tried raketu, a voip provider with very good rates but which does not yet provide sip support.

What is the quality like?

Have looked at them but not tried them.

It all depends on where you are located and where their server is. when you are in greece using a us based service the signal has to go to the USA which does take some ms extra.

I prefer to use only sip based solutions as I can program these in any sip hardware device and also in www.pbxes.com or other asterisk based servers.

Yes I would also prefer them if they had sip. But they offer some good rates and if the quality is good it might me worth looking at.