Yes, a lot of these are much improved by reverse-engineering them and adding a few tweaks to modernize them. Many of them have added support for different display aspects, since most retro games are tied to 4:3. I downloaded the new RE of Sega Rally the other day and it was nice to have full proper widescreen.
I personally like to play with the graphs of the Totally Games version of Tie Fighter but with the iMuse music of the original. it's the best experience.