I had a T1. I have a Kobo Aura H20 now and I would never go back. I suggest getting the new Kobo Libra H20. It's a 7" screen.
- Hardware buttons
- 7" Carta screen for better contrast and fast response
- Faster
- Handles hi-res images much better
- Newer version of RMSDk
- Can install KOReader or Coolreader but there's really no need
- Collections can be managed with Calibre just like the T1
- Overdrive support
- user font support
- 300DPI
- and more
I would not go with another T1 as it is slow and doesn't play ne with high-res images