Thanks Chock for the advices!
I like long flight more then short, so the PMDG 777 would in that case be a good choice.
Handflying, not so much. The automated stuff is more to my liking.
I do enjoy study level aircrafts more, because it gives a challenge and better training, I think. So the A320 or the IEXG 737 is then the choice in that case. But the PMDGs I learned thru forums and videos is tested and granted by real Boeings pilots and therefore study level too,
but I will wait for pmdgs to (eventually) release their aircrafts for X-plane and buy it then.
It all comes down to which platform i use the most, and that is X-plane. So the choice would then be IEXG 737.
But I think that the FSL A320 will be more fun in the long term, because it´s a newer plane and most airliners uses it. So maybe I buy it for FSX Steam and then upgrade it for P3D v4 (hoping V4 will be in same visuals as XP 11).