living history versus reading about it
Borland was head and shoulders above MS Visual C. MS Developers developed with it, using MS VC for the final compile, as there were hidden hooks in the MS flavor of the C compiler (withheld from Borland, of course). Do you want to mention the poaching MS did to Borland?
Office better then Corel - I assume you mean Word Perfect? Once again, API's were withheld. If you'd actually experienced history instead of just read about it, you'd know this was a Big Deal.
I agree with not blindly trusting, but I must say, past behavior must be taken into account too. Did I use Silverlight? No - as it is MS-only tech. Regardless of the tech, if it is MS-only, I avoid it.
http://en.wikipedia.org/wiki/Category:Microsoft_criticisms_and_controversies