... yes size matters but with strategic bridle placement it can be done, but there doesn't seem many I've come across that can.
Stability is a big issue with us big boys, a usually good kite is rubbish under a big guy when its either loaded up during a jump or even just edging hard. The LE would fold in the last quater around the bottom bridle area connection and this bending will completely upset the kites flight,,, like I said, feel like rubbish. The kites end up not delivering more forward power but more truck (down wind pull) but once the LE is "not" bent, forward lift comes back. This for a big guy is no good.
I'm a heavy dude too (120 - 125kg) and currently riding a 2013 Dyno 17m and Rebels which can hold up to me. The Rebel especially good at holding up to the weight/power but then again they don't have bridles. The Dyno does have a bridle and only in big power loads does it sort of bend but not too bad, not like a lot of other brands.
There is one exception to North that I came across and that is the Zephyr. Its LE is a little bigger by the other models in the Ozone range, Edge for example, and it seems to hold up very well indeed. The few times I tried it in strong winds not one bend or fold so it suits us big chaps well. It did how ever get a bit more bar pressure as the wind increased but to me it wasn't a problem.
One other way we as a user of the kite can sort of get around the bending LE and that is to pump up the LE to very high pressure but this has its downsides too, especially if your going to bang it in the drink when learning stuff. Splitting seams is worse so I don't like pumping kites too much.
Cheers,
Robbie!