Want a QWERTY slider; Moto XT860, Sam Captivate Glide or Sony Xperia Mini Pro?

[xraycat]

I've used a Nexus One, HTC Aria and now a Galaxy Nexus. I want to try out a new form factor in a side-slider QWERTY but can't decide on which to buy second hand. I want to try out different ROMs and mess with it a lot, my main phone will remain as my Galaxy Nexus.

I like the XT860 (Canadian Droid 3) for it's screen and 5-row keyboard but from what I can tell there isn't much of a hacking community and alternative ROMs because of its bootloader. Also, support isn't as great as the Droid 3 because there aren't as many users.

The Captivate Glide seems nice but I haven't really checked out the developer community for it yet. I expect it'll be better than the Motorola though.

The Xperia Mini Pro seems like my favourite right now because of its compact size and great developer support. I can also pick up an unlocked one from ebay for under $200.

Can anyone help me pick or give me another alternative?

[Drillbit]

I would go with the Glide if its the hardware, but the Xperia here is getting the Android 4.0 upgrade.