I think you're going to be quite impressed.
I remember when I went from my v1 Touch to my Aura HD... that was impressive. Given that the T1 has the same screen as a v1 Touch, I imagine your reaction will be similar. The Glo HD may have the same size screen as the T1, but as you've said, the difference in resolution is astonishing. Plus, I'm sure you'll love the front light. I can't imagine having a reader without one now.
Do a look around the forums. Side-loading fonts onto Kobo devices is fairly straightforward, as long as you name the font files using the proper convention. The
Summary of Modified Fonts sticky topic has all the info you need.
Enjoy your new reader!