I have a script with some rsync commands for backing up a load of folders with photos etc (I also have time-machine but this provides me with duplication). The backup is running between my Macbook Air running Lion (10.7.3) at the moment to my Windows Home Server (V1)
Most times I run rsync with lots of files its hanging half way through. I also found it to be rather slow. On further investigation it looks like the rsync that ships with Lion is fairly old – v2.6.9
After downloading and installing a more recent version – Rsync v3.0.6 it now no longer hangs and also runs much much quicker