Well I have just placed an order in with Dark Art's Miniatures for 30 new Urban Themed Bases. Much of my army uses Dark Art's Miniatures themed bases as they are great quality and cheap. I love these bases.
Dark Art Miniatures - Urban Themed Bases
$5 will net you 10 individually molded bases. I will often use a small drop of super glue on my figures to secure them to the base they come on and then get them painted. When the themed bases come in I wash em, spray em, paint em and then transfer the mini to theme. As they are resin they do need pinning to keep the model on. I originially didnt think about it until my models began popping off in a stiff breeze.
Also, as you will notice, they are resin. They are durable resin but resin none the less. Other people have complained about bubbles in the product but I have yet to experience this and I have bought the urban Pack (60mm base, 5x 45mm bases, 20x 25mm bases) twice and about 20 bases on their own, no problems. My friends first batch of Lava Bases did have some bubles among the lava and edges of the rock on a few of them but were barely noticeble.
One problem they do suffer from though, as I am sure many themed bases do, is that the bases is filled in. This makes the model slide around a lot on sloped surfaces as it cant grip anything. I am sure a quick spray of textured spray paint would help eliminate this I dont feel like doing that so I go with it. Its a neusance but hasnt come up a whole lot. The cost and details in these bases far outweigh their little problems.
2nd Platoon is almost fully built though with 5 squads, a command, 6 autocannons, a couple melta and a handfull of plasma.