I have a few plasticville items and like them. Some are OK out of the box, others you might want to consider painting. I have the trailer park and I think I have a blue, silver and hot pink trailer in my set. I think I sprayed them with a Krylon Matte finish to take some of the plastic look off of them, but the pink one at least could use a new paint job.
You do have to glue them together. Once they're together though, they look pretty good. Especially for a carpet central (which is what I have). I'd post some pictures of my buildings, but my camera is in Germany with my dad until he get's home tomorrow.
I have the roadside fruit stand, the trailer park (three trailers and three flags), the union station and the hobo junction set (which brushed with black paint and wiped it off so they look weathered, came out pretty well).
If you're going to add LED's to them, I'd probably consider painting at least the insides black to prevent light from escaping. I've never lit any of mine up so I don't know how bad they are. I have a K-Line suburban station (similar to the plasticville station) and it was really bad for light seepage until I painted it.
