I was forced to upgrade (my 655 died after 13 months). I've run the 1.10beta for a while now, as I was really frustrated by some of the broken things in the original release. Even 1.10beta had its issues (e.g., no 802.11b).
However, now with 1.11 out, I think it's a good improvement on the 655. Some things I like:
- CAPTCHA during login
- Website filters work (didn't on 655, but I'm still testing)
- 5GHz works, so I can run my N-devices at full speed
- Apparently has a faster processor, UI is much snappier
- Shareport with Mac support
- Connections seem pretty stable
Would I buy it if my 655 hadn't broken? Only if I had $120 burning a hole in my pocket.
