Hi bierbaron,
I was already aware of it by talking with GordonJ at irc (ForeverChat), it looks great and going by what he told me it should also work as expected.
AFAIK dats should be placed in the dats folder with the same hierarchy as the desired roms folders. That and the ability to scan various dats at once make it sound very useful and if i was collecting i would give it a try
It shouldn't be compared with TIM since TIM was planned to do a lot of different things and ended up doing things the way we know.
RomVault should be seen as an alternative to clrmame pro with some nice and new features that could make it perfect for managing large numbers of dats / collections using less time (one scan vs N dats a time instead of one scan for each dat) and giving you a nice easy to use GUI.
I'm not saying it is great and didn't even tried it but the features available sound great and alternatives are always welcome