This is almost a 'how long is a piece of string question'. I think it's also a case of you get what you pay for. I've had a set of Alex Supra BH for almost two years now, and they've copped heaps of squirrelly landings and crashes, with only a slight wobble to the left and right. However Alex are not the most renowned of rims ( at least not in the MTB arena). DT make 5.1D's, which Sam Hill (amongst other pro's) has been known to run. They are light, but are only rated as an all mountain wheel. They are a bit softer, so may minimize the pinch flat problem, but obviously will come out of true easier. The DT 6.1D's are heavier, but obviously a lot stronger. Your answer (I'm sure you've already figured this out) depends on your concern for weight. Mavix make a lot of nice rims. If you already have FR440's, there's no point buying a proprietry wheelset like DEEMax. There are also problems associated with buying an entire wheelset. Mavic make the 721's, and 729's. The latter are a little heavier than DT5.1's, but not as heavy as 6.1's, and from all reports are way strong. I'm pretty sure that both these come in 32 and 36. Then you have Halo, Atomlab, Dice, Intense........phwew.