It's very usable when paired with PcManFM, and there are a plethora of themes available. Customising is done by an intuitive config file. There are tools to auto-generate the application menu, so you don't need to toil after installing a new program.
The hardest part was setting up automount to handle my network drives and USB drives - no gvfs here! A result you'll welcome if you like sane paths to mountpoints.
I use Fluxbox since the first version. Very easy to customize. I've just an issue with Firefox, the Firefox windows doesn't want to play with Fluxbox (on Debian)...
I think this is a bug in upgrade path, I have my normal profile with this problem (and a lot of accumulated things) but if I launch Firefox with a fresh profile then it works nice.
