Borland made the best dev tools in their day, but they sorta lost the edge early in the Builder run and other tools became more desirable. At least, that's why I stopped using them.
I don't know about Mac support. I did Apple development during those days as well, but I didn't use Borland tools for that, I used CodeWarrior.
LightSpeed C, later renamed THINK C, had the Mac market sewn up before CodeWarrior. They had an excellent hypertext help built in, before web browsers. They were bought by Symantec, added C++, and then got beat out by Metrowerks.
I think CodeWarrior was just the superior IDE for anything Mac back in the day. I wasn't a mac guy, but I recall it basically being the only option my buddies would consider back then.
I don't know about Mac support. I did Apple development during those days as well, but I didn't use Borland tools for that, I used CodeWarrior.