I've not used them with
GW's kits (although the larger panels DO work height wise.).
I've combined them with foamcore stuff I've built myself AND with miniaturescenery lasercut
MDF terrain, though.
I've got to upload pics of the newer stuff. I might have some of my older stuff I used for necromunda on my photobucket, though.
(only picture of the stuff that survived. Sadly, the terrain itself did not survive to this day. It had a board fall on it at a tournament (during unpacking).

A few things to know.
They are three different ranges of kits and aren't interchangeable. Hexagon won't work directly with platformer or the power plant kits.
ALL benefit from gluing together. ALL of them. Whilst the hexagon stuff is fairly sturdy for clip together stuff, it benefits more from being glued together. Regular model plastic glue will work on it (as it's all made from the same kind of polystyrene as model kits are).
This piece uses parts from another related (as in made by the same mob) kit called "syberclicks" - to make the catwalk around the building edge.