twest Yes, the forum isn't very active (unlike this one). I believe they've hired new people to manage it now. The community is still not as active, though.
What I really appreciate is the attention they've given to translations and localization from the start. I've tried many other billing systems, and none of them handle language and currencies as well as this one does (which happens to be exactly what I need). They all work fine in English and with USD/EURO/Pound, but things get messy when you try to use more unusual currency formats.
Currently, it lacks several features, such as one-off invoices, more domain options, etc., but I can manage so far. However, being a small business owner, I'm not sure how well it would work for bigger companies.
I've seen people get upset, frustrated, and eventually bail. There's a bit of a learning curve involved, I admit. I hope they catch up soon with the missing features.