Okay, with my recent troubles with my K1500 and a nice looking cheap
K2500 standing at the dealer, I asked my self: which engine is
superior?
L65 doesn't have MAF and EGR valve, right? Meaning less parts...
So in my mind the L65 would be the better engine, but what do the
real experts on this board have to say about it?

I *might* buy this K2500, if I can get a good price for my K1500, I
don't care anymore for the sidestep look, its just my split bench that I
don't want to lose):h

The "F" engine is the one to have.

Yeah I thought so :)

But all in all, the differences aren't that great right? Only
difference is EGR, MAF sensor and a different PCM, right?
Or is there more to it?

It's the way the pcm figures boost requirement. In the "S" engine, its very dependent on Egr/vac raeding for WGDC, or the % of boost you're cycling.

Losing the MAF frees up intake air flow

Losing EGR removes exhaust-dilution of developed power

Losing EGR passages in intake maniforld lowers intake air temperature

Pre-cup configuration is for power, rather than economy

PCM non-EGR programming allows more developed power

2500 gets larger brakes

Else - samo samo