My 97 has ABS, leather, and the optional 3.27s, so it's pretty well equiped.
Sometimes I like the ABS, but on plain dry pavement, I feel like it prevents good weight transfer and increases the stopping distance compared to using my right foot. Of course, in the snow and rain, I am glad to have it.
On 99+ stangs, I believe the TCS is attached to the ABS, so if you have one, you have both. They use the same sensors after all.
For 94-98, Cobras had ABS standard. It was optional on GT's and V6's. For 94-95 it was a 3-channel ABS system and later became 4-channel in 1996.
For 99-04, Cobras, Bullitts and MAch 1's had it standard. I beleive for 99-00 GT's had it as an option with the deluxe package and standard with premium. Also, You could get ABS, but then for 99-00 you had to add traction control on for $300.
For 01-03, i beleive ABS and T/C were a packaged deal and standard on GT's.
For 2004, it became an $800 option on the GT again.
I don't know how the 94-98 ABS system is, but on my '03 is was quite excellent. It didn't intrude much and I autocrossed with it and it behaved perfectly and predictablle. No annoyiing chattering when trying to stop. You could feel it work and it didn't suck.