To give folk an idea of scale I’ve taken a couple of shots with oddments that were lying about. I’ve not got any Battletech or Heavy Gear mechs so these will have to do. A few people tell me that they thought it would look good with those ranges, so I know it’s a consideration.
Stunt models include some GW Epic land raiders (of 2 vintages), an old rhino, a 40K Space Marine and a 15/18mm AB british Napoleonic line infantryman.
The DzC building is wonky because I’ve not stuck it together yet – it’s just folded into place. The shot below is more of a normal angle to view these things from.
Hope that helps.
Quirkworthy 
I suppose they wouldn’t work for 6mm then, definitely 10mm+; even 10mm looks like it might be too small. The AB mini, 18mm, looks just a touch big.
They are designed for 10mm and look like big, imposing municipal buildings in that scale. I thought the AB figure was worth including as it nearly looks right.
Interesting. A good perspective!
do you think they would be OK with 15mm sci fi ranges like the old laserburn stuff?
I think 15mm is a bit big. Look at the size of the upper level windows rather than the grand facade on the ground floor. Not out by a long way, but could be enough to look a bit strange. It depends on how picky you are (I’m too picky).