I've been using it for several months (actually running it as a VM under Hyper-V).
It is very reliable - the only problems caused by me messing about
It's pretty easy to use and can be reinstalled ok without losing previous data. It is good for what is was designed for - file sharing and backups across a Home network that has one or more client desktop/laptops.
The Media sharing is not brilliant if you have a huge music library and it won't stream some of the latest video codecs. There are documented ways on how to bodge it into using WMP11, which is better but still not a 100% fix for above problems.
What hardware were you thinking of? Runs fine with 512MB (any more is probably a waste) - I'd suggest gigabit Lan if possible (of course you'll need an appropriate router/hub - I'm eagerly
awaiting this to get to market) and several disks (so you can get data redundancy).