As someone who's had about 8 different Blackberrys and 3 Treo phones, including a foray into WebOS (still have my Pre phones), and now Android, I would recommend the Q10 over the other choices for a few reasons:

1. The Q10 has the best keyboard I've ever used. I own both a Q10 and a 9930 and love the Q10 keyboard (the 9930 was the best until I tried the Q10). I've owned probably 10 different qwerty keyboard phones.

2. If you have a Treo still, you aren't one of those app people who insist on having Instagram and all the other silliness. BB10 is lacking, for sure, but has many core programs and the catalog is still expanding.

3. It's terrific for messaging - BBM, email, the hub that unifies everything, notifications, etc.

4. Web browsing is actually awesome on it - much better than previous versions.

5. There is no replacement for a qwerty keyboard.

The android phones with keyboard are mostly cheaply made with low end processors that are designed more for ruggedness and industrial use than business professionals - think field techs and the like. I personally would also pick the Q10 over the 9900 just because Blackberry is trying very hard to move to OS10, which is not going to be available on their older models.

As someone else said, if you have a tablet device, you're getting all the same functionality and the app richness from and android/ios device which would give you the freedom to have a phone that does a few things well (messaging and calls). A lot of people talk about the concept of three screens - the idea that you have a PC, a smartphone, and a tablet. I vary that a little bit by having two cell phones - an android phone for music, video, heavy web browsing, reading, and app enjoyment, and the Blackberry for messaging, calling, any email, BBM, and throwing at people. It's worked well for me and I like that I can put both in my pocket.