Out of that list, the only thing I personally found useful, is the ACSI port.
It allowed me to use teh STE's HDs until I got hold of a proper SCSI Cable.
In fact, I still used it for quite some time afterwards too, in a kind of "My Atari has Dual SCSI - ner-ner-nerner-ner" thing.
External Disk Drive, by this I assume you mean floppy? - I have to admit that I only ever had the need for more than one floppy drive on my first ST before I had a Hard Drive, so this I dont find a valid arguement.
REZ - Ok, thats a big issue and also a non-issue for me too!
After moving from the STHIGH to TTMED, it felt very much like I was living on a rainbow. When I went to the Falcon over my TT full time, I used 256 colour Mode and I loved it, but I also noticed a massivce slowdown in display speed. In fact, its only since the CT63 that the display has been useable for me.
I still to this day say that the TT without a Blitter is faster than the Falcon with...I really do need to get off my arse and run some tests to verify this.