I have a lot of the elves, a TON of the undead and some of the dwarves.
IMO: I really do not like the elves. I think they are way too frail looking, plus the "Sea Guard" are just 10 archers and 10 spearmen. However they do work in my HE army as long as I keep them in their own units, so all is well. I should also point out that I had the Elven Cav (the metal ones) converted to Blood Knights, they look awsome.
The Undead are truly amazing. The ghouls are easy to paint, easy to put togeather and look the part. The skellies are harder to paint but look better than the GW ones IMO. The Black Knights are sooo much better looking than the GW ones, my only gripe is the lances are VERY fragile. Seriously I think I'll need to solder one back on. I also have 50 GG being painted by a pro, should be back soon, the ones he finished look great. Also the BSB is awsome, another pro painter is going to paint that one for me as well.
For the Dwarves I like the cannon better than the GW one because it seems more to scale, as far as the dwarf models, eh. Maybe I just don't like dwarves. Only got them because of a campain where I got to select allies.
As far as the Kings of War game, it looks like it has potentail, but it seemed a bit simple to me. Maybe in a year or two I'll seriously consider giving it another try.