FYI, there are a ZILLION threads and posts comparing many of the new smaller amps. I would suggest doing a search by amp name (i.e., Shuttle, LMII, TecAmp Puma, Markbass, GKMB2500, TC450, Markbass F1, etc., etc.).
You will find a ton of information (with the positives and negatives of each of them) on all of these heads. You might have to work the search function a bit, but there is a lot of wonderful info.
Within a month or so, as the new Markbass amps start to ship, you should start seeing some user reviews of the new Markbass LM line of heads, along with the new Euphonic Audio offerings, which I understand are just starting to ship. There is a very nice review of the new Shuttle Max12 in this months Bass Player also. That looks like a killer head, especially if you have two 4ohm cabs.
Lot's of really nice stuff out there right now, and more stuff soon to be introduced!