I have owned one for a couple years now and pushed it hard. I can't imagine a better lathe for a better price.
The only thing different I can see with the bigger Jet after running one for a day this past spring, is its heavier (more stability, more than needed) and it will go slower if you need ultra slow for CA finish or the likes.
I would buy another Comet 2 tomorrow if my current one somehow was stolen or what ever.