Aquiring more Androids

We've been using HTC MyTouch for our data collection. However, there are a
lot of new Androids on the market. Has anyone used anything other than the
GI or MT3G for data collection, and how well has that worked out?
Any warnings to stay away from this or that?
Any thoughts on the best place to purchase them unlocked?

··· -- ☞§※⌘✈☂ ~Neil