I'd be happy to offer any information and experience I have concerning Fat Llama. I'm not really bothered about them being a competitor. As far as I'm concerned with my business hat on, I'm in favour of anything that propagates the idea that it makes sense to hire expensive photographic kit when you need it. Let's make the pie bigger rather than worrying about the relative sizes of our slices.
But the interesting and slightly surprising thing is that I've heard absolutely nothing about Fat Llama from our customers. Not even anyone asking about comparative pricing, etc. Nada. Zilch. I'm not entirely sure why. One possibility is that peer-to-peer is very much a minority activity, at least for photographic equipment. (And to be honest that strikes me as quite plausible, given the obvious difficulties around peer-to-peer lending of expensive and fragile kit.) Another possibility is that there's just zero overlap between their customer base and ours, though that strikes me as somewhat less likely. But I just don't know.
But anyway, if you want to go down the peer-to-peer route, it can be very cheap, not least because the owners of the equipment don't have overheads like staff, offices, IT systems, and so on. Just make sure you check out the lender thoroughly: How confident are you about the condition of the equipment? What backup or support can you expect if something goes wrong? What is their policy regarding cosmetic wear and tear? Basic stuff like that. And make sure you understand the insurance position. And make sure you understand the Fat Llama terms and conditions - there's some important (and to my mind rather strange) stuff in there. Good luck!