Sorry, Franko, but I'm going to have to call BS here. I did use 4.0 for some time without RTG and it was in no way, shape or form, comparable to a "chip ram only" amiga.
For a start, screen dragging on AGA always worked just fine and uses the native chipset to do it in exactly the same way as all previous versions of the OS did, as you can see from these two screen grabs (right down to the number of ISD scanlines)
Above images were taken from the days when I was beta testing and represents a quite early stage OS4. WB was 16-colour PAL Interlaced (externally flickerfixed) and DPaint HAM8 PAL Interlaced. Performance was absolutely fine on both.
Feel free to jump on the "OS4 is shite" bandwagon, but unless you applied precisely the same common sense approach to screen resolution/depth that you do on 3.x, you can't blame OS4 itself for AGA being a let down.
OS4.0 always ran fine on my BPPC/200Mhz/256RAM with AGA.
