if it's any consolation, I've ridden the one mile trails hardly at all, maybe one time each, and RT is better than overnight for sure! backpains is fast and flowy but pretty straight forward, just watch out for the tight steep berms!
Hm I'm somewhat surprised that we're doing RT and Backpains, that's just my fitness talking though.
For those that want the Beta, RT is dusty and loose in places, and there are lots of mini-stumps and such to watch out for in the first couple of sections. If you're going to pre-ride anything, I reckon RT is the one…the other trails are all pretty much fast, flowy senders, really really fun trails.
One major thing to be aware of, mosquitos are BRUTAL right now, just saying…keep your PSI high and pray you don't flat ;).
Good luck and have fun!