If it had been launched with a 68020 it would have been superior to the A500 all around. The 68000/ECS combo was totally dead in 1991-1992.
That aside, the compct nature made it a better choice for people on the go, and it was a good starter system for people who were still hanging onto their C64 systems.
As far as expansion: The A600 lacks any type of reasonable expansion bus. The best you can add to it are RAM cards and some 020 (and if memory serves 030) cards that clip over and onto the 68000.
I believe Apollo made an 020 or an 030 card which was popular for people who wanted near A1200 performance, but no real graphics expansion was ever released, leaving the A600 in the ECS set of machines, not the AA set.
I also like the small compact and sexy design, but it was never a choice for me (Toaster user). I always stuck to the larger boxes and at one time had a Toaster 2000 and two Toaster/Flyer boxes running at once (A4000 and A4000T).
Overall the best Amiga model ever relesed was the A4000T. Out of the box it did the most, and had the most expansion capabilities. The A3000/T and A2000 are my next in line. The A1000 was probably the best in overall design though for what it did and what it could be made to do in 1985.
//R//