I picked up the Kollector's Edition on Friday for PS2. So far I think this one is a huge improvement over MKDA all things considered. There's just so much more "kontent" its ridiculous.
I think MK1 pretty much is arcade perfect. The game is being played though an emulator and the machine is set to free play. Also, the music and sounds are the same as the arcade (I remember someone saying they weren't). I just played a few games in Mame and everything sounded the same. Also, the parts with slowdown (when JC gets knocked out of a shadow kick or the credits)...slowdown in the arcade version as well. The music cuts off in the arcade version and everything. The only thing that I can think of that is different from the arcade version is that the home version feels just a tad faster...and thats an improvement IMO.
The only things I don't like about this one are the smaller krypt (400 koffins in MKD vs 676 koffins in MKDA) and the fact that Johnny Cage, Sonya, Jax, Shang Tsung, and Quan Chi are in Konquest mode (and can fight them)... but you can't play as them in the other modes. It seems like such a waste. I mean, the models, movesets, sounds, etc are all there....make them playable for crying out lound. I don't care if some of the other characters use a few of their styles now.
Anyway, Ermac kicks freaking ass. He used to be such a sucky character but his combos are just sick. I love how you can keep levitating people over and over for combos and his D,U + X (float) manuever is great. Li Mei is still a powerhouse as well.