ive been beating a singletrack front on my dh bike and ita still holding up after a few years of dh runs, jumping and riding rocks w/ a flat multiple times, i also have ryno lytes on my slolomn bike and the rear has been around on a couple of different bikes sence about 2001 and it may be wobbly but it still works...i have been relly impressed how well these have held up...im running em on my new dh bike instead of the singletracks because i havnt seen much of a difference in durability so ill take the lighter rim..
I like Ryno Lite XLs a lot. They're stiff and strong. The Singletracks I had were really buttery and flatspotted easily, but they didn't pinch flat very easily. I would personally go for the Ryno Lites, especially because they're lighter.
personally id go for the single tracks just of the fact that the rhynos are a pain to put tyres on them (various models)
thats my experience with the 2 rims
both seemed to hold up to my abuse the same way
My vote is for the Rhyno lite XL I am running them on my DH bike now with no problems. I have used Singletracks in the past and they dented and flatspotted easier. On my dirt jumping bike I have a Rhyno lite that has 1/2" holes drilled out between the spokes left over from my trials days. This rim has seen 3+ seasons I have not even had to true it.
Rhyno lites can be a pain to get tires on and off. You really have to make sure the bead of the tire is in the center of the rim and use the thinnest rim strip possible. Or just get big beefy metal tire levers Michelins also mount easier than Maxxis on the Rhyno lite.