Going back a little earlier...
The A500+ I think was a good machine for the price. I would have left it as it is.
The A600 had cuteness going for it. It should have had a 14MHz 68000 however, just for a little more pep, especially for 3D games.
The A1200, much as I loved it, was made to a price point and it showed.
Firstly, I would have had a 1.76MB floppy disc drive. The 880KB drives were horribly limited by this time.
The PCMCIA slot should have been an A500 style sidecar slot with the full 32-bit bus available. Drop the internal trapdoor expansion apart from making a SIMM slot (or two - 1 chip, one fast) available for memory expansion.
AGA was a bodge. The blitter should have been a full 32-bit blitter for a start. I would have had more audio channels in Paula, and the capability to run the HD floppy at full speed.
A native, fast, 8-bit chunky mode was needed. Also sprites should have been arbitrarily sized (even in steps of 16 pixels) and (effectively) unlimited in number, 4, 16 or 256 colours without having to "layer" the sprites for more colours. A scanline buffer that someone mentioned would have been good. Ability to do 800x600 (and 1024x768) resolution non-interlaced, albeit in fewer colours.
3D capability isn't a consideration for me. That would have been in a follow up to AGA. Same with 16-bit audio (although hardware support for that clever 14-bit channel mixing that required loads of calibration would have been nice). Same with FPU sockets - leave them for the expansion boards.
Maybe I would have made the base A1200 1MB chip and 1MB fast. Especially so for the CD32.
The 68EC020 in the A1200 was a cost reduction thing. Shame that Commodore couldn't negotiate Motorola into using a faster chip - e.g., a 20MHz+ 68020/68030.
