I completed a couple of 6mm Irregular Miniatures fantasy Hordes of the Things armies. (Whoa, I completed something...) Read on...
I bought these after seeing the Fellowship of the Ring (yes, FotR...) for the fun of it and have poked at them since. I got in a snit this weekend and finished them off. I figure you could easily paint an entire army in a day. Mine took a bit longer because I used the Miracle Dip (which makes your net painting time faster, but has to dry overnight) and my basing takes forever. Here they are:
That block is about 8"/20mm square, plus these aren't slimmed down armies but have lots of extras for variety, so it's obviously rather economical on space (although these are based on 15mm sized bases, so that's not a function of the figure scale). Here are some 24 point armies deployed:
I found the figures fun to paint. It's a little different-- while in larger scales you can enjoy painting a particular figure, in 6mm you can blow through the figures and enjoy the overall effect. There is more room for interesting dioramas (not that mine are that interesting, but they were fun to do). Here are some closer pics; you can also poke through my fantasy gallery for some older pictures:
I poked around with HotT 2.0. It seems like a decent enough set and rules, if a tad difficult to actually read. I've never been particularly attracted to WRG rulesets, especially since they're largely geared towards Ancients (not my cup of tea) and competitive play (not my style of play). Still, for a quick friendly game with armies you can paint in a day, not bad at all.