Brings back memories of writing 68K assembly, back in the day when writing raw was the difference between screaming fast and dog slow. 6502 was even more fun.
The 6502 was fun and it was the first assembly I programmed[1]. The 6809 also deserves a look if anyone is reviewing old instruction sets / assembly code. I am still not sure which of the three I preferred.
One of the biggest advantages over the 6502 was the ability to work with 16-bit registers. X and Y were 16 bit, and a user/local stack pointer was added, U. Even the A and B accumulators could be combined into one 16-bit register, D.
It's one of my favorite architectures. You could do a hell of a lot with very little room.
1) on an Apple II, sadly not on my Atari 400