I quite like these, even though I wasn't sure about MDF board...
No gaps at all even though they go together like puzzle pieces.
Not difficult at all mind you, in fact they were very easy to put together, they make it very hard for you to put it together wrong.
I used white glue for the landing pad, but then I switched to super glue, it was much quicker and worked just fine.
Here are the pics before I painted them:
The roof is cardstock (I think) with laser etching, I tied it while it was drying.
The Landing pad is very cool...
And perfect size! The spaceship fits on there great!
They are quite a bit bigger than the GZG buildings, although the doors are the same size, I think they will fit in just fine, since I'll be giving them the same paint scheme.
Some comparison shots with a 15mm figure on a base:
I really like these, and I look forward to ordering more! They are really cost effective too.