I chose BT since it is...
A full featured and beautiful CSS (Cascading Style Sheets) framework which combined the best of Blueprint, Tripoli (hence the name), Hartija’s print stylesheet, 960.gs’s simplicity, and Elements’ icons, and has now found a life of its own.
I liked 960’s grid but it did not have a typography companion, also I prefer the 10px margins over the 20px margins in 960 (but 960 has a more flexible grid but almost the same syntax as BT). I liked Blueprint but BT had nicer Typography. I could not understand Tripoli, I don’t think they have a grid system? I opted out of Emsatic since the reported IE issues. BT was the most straight forward, get it all in one place framework I found. All I needed was there. With the others I would be tempted to gather bits from one or another and end up with a mess.
One thing I liked in BT was that 1em = 10px which is great for fast calculations. I did not see how others treat the conversion factor, so this could be a mute point.
I wanted to use
xWisdom’s Raxan as it is also a javascript platform, but the learning curve was too steep for this quick project (but I will definitely dig deeper into this since it seems like a great tool). Very cool to put js and css under the same package
My concerns about BT are about it originating as a mashup, but after reading up on it it seems that the author has taken it beyond into a life of it’s own. I have another freebie and a personal site to work on over the holidays and I will be using BT for sure (or maybe Raxan if I get some time to try it out).