Got my R44 today. First impressions are that the preamps are a little more quiet than the R4. Feels nice and solid, a little more so than the R4. Other than that it seems about the same. The ability to link another R44 is the selling point for me, so it looks like I will sell my R4 to purchase a 2nd R44.
I'll probably sell my Alesis HD24 as well since I almost never need more than 8 tracks.