Hi Gurrah, I asked Genseng this the other day. If you have TW3 you will have an option on your account to upgrade to TW4 for 100 Euros, once it has been released of course.
I only bought TW3 yesterday, i was told that there will be a 100 euro charge for the upgrade, and that it was best not to wait (though i was talking to a sales person )
Hi Steve, TW4 is still in Beta and could be months yet before all the bugs are ironed out and then after Alpha release there is bound to be a period when more bugs get discovered. Its worth the wait and you did the right thing by getting TW3 as only Easypano know how thing are progressing on TW4.