This thread is a few months old, but I figured I'd revive it as I just finished the Rae Lakes Loop in a day this last Saturday. 16 hours 21 minutes starting and ending at Roads End. Not super fast, but the trail was a lot less conducive to running than I had remembered, so I'm happy with that given that I couldn't safely run much of it.
I did it counter-clockwise with the intent of getting the steepest part out of the way quickly, and having a long more gradual downhill on which I could do some running after Glen Pass. I think this was the right move. I got a little bogged down on the last part of the climb up to Glen Pass, and then felt sluggish while passing Rae Lakes down to Dollar lake (which otherwise would be pretty good running terrain), but recovered pretty well after that and was able to hike very quickly, and run where the trail was smooth enough to allow it.
Craig, if you haven't done this already, I'd say that you probably don't need to worry about bonking and needing to stay out overnight. Based on your other posts, I get the impression you do a lot more training than I did, and I managed fine. In fact, while I was ready for it to be finished by the end, I felt fine and could have continued farther if I had to.
On gear --
I agonized for a while about whether or not to bring poles because I had no convenient way to affix them to my pack during what I anticipated would be the significant amount of running. I have the Gossamer Gear Lightrek 4 w/ straps, and ultimately decided to take them and just carry them during the running portions if they wouldn't stay still on my pack. I'm glad I did since the trail turned out more rocky than I remember. I have to say, these poles are amazing. They were rock solid and the straps were super-comfy used nordic style (I have no idea how those of you that don't use straps do so comfortably, but that's another post). Having them to navigate, and launch myself over, rocks made me MUCH faster. I was able to quickly lower myself down steps and stuff with a lot less strain on my feet, knees, and hips, and with a lot more speed because I didn't have to be as careful about how I was landing. And the poles were so light that I could just tilt them up (without even removing my hands from the grips) and run with them when the terrain allowed it. Even on the longer running stretches, it never got uncomfortable doing this. The poles are just phenomenal.
I used a Nathan HPL #020 Race Vest as my pack. It's the best pack I've ever used for running because it moves with you instead of against you. It's supremely comfortable. Unfortunately, this model didn't have enough capacity for the extras I needed in addition to water (i.e. food, windjacket, water treatment, sunblock, first aid kit, and a rented satellite phone that my wife made me take). I had to have a tailor sew some attachment points on and strap an additional zippered pouch to it. This worked well once everything was cinched down, but it was a very annoying and time consuming process to get anything out of that pouch because I'd have to undo the straps, then repack it when I was done, and spend a while strapping it back on, taking care to keep the weight distribution right so it wouldn't swing around or slip loose. Annoying. If I were doing it again, I'd get their Synergy 3.0 pack for the extra capacity.
I used a steripen for water treatment and it worked flawlessly. It was reasonably fast, and it was nice not to have to wait for chemicals to work.
I also used Symblissity LevaGaiters which were perfect. My favorite gaiter by far.
Shoes are so individualistic that this might not be useful for anyone, but I used the La Sportiva Wildcat (I have orthotics that I put inside). They worked very well. I got no blisters, which is amazing because I ALWAYS get horrible blisters. I did manage to bang the toenail on my left foot big toe a few too many times, though, and will probably lose that nail. I don't think that had anything to do with the shoes, though (didn't happen on the other foot). And that was my only casualty other than a little bit of muscle soreness.
I used drymax trail running socks. I've tried A LOT of different kinds of socks, and these are the best I've found by a good margin.
For food, I used Infinit & Hammer Perpetuem powdered drink mixes. They worked great. I also took a half a turkey bagel sandwich with cheese, which tasted awesome just after Glen Pass. I ate a few clif bars, too. I ended up taking too much food. I didn't eat/drink a bunch of the drink mix or a dehydrated refried bean & quinoa flake concoction I brought along. I just never felt all that hungry. Thankfully, I never had any stomach problems.
I think that's about it. Hopefully it's helpful to someone.