This is a no brainer for me Kathy. I have used both, extensively and Dragon wins hands down. The language you use for navigation is a little more intuitive than Win T2S.
I have had Dragon about a year counting a demo download which I believe is still around, and I write most of my posts here, especially the lengthy ones. I also surf, interact with programs, bookmarks, all applications that I commonly use.
I don't know what is out there, but Dragon keeps up with my speech no matter how fast or slow I talk, sitting up, laying back. The "Learn how you speak features of both are good" Dragon has better sentence structuring and proper word usage - as in:
"They're there in the car with their friends" would be nailed with Dragon, same sentence I know I'd be fixing with Windows.
PS... too lazy to plug the mic in, using it elsewhere right now so this was hand typed - no one to blame but me :)