This is the third time I've stayed at the UCLA guest house, but I probably won't be coming back. First, the positives: It's a fantastic location if you're doing something at UCLA, as it's located right on campus. The desk staff is friendly, helpful, and competent. There's a "business office" with free desktop computers to use and free printing (handy for printing out a boarding pass for your flight out). Breakfast is free and good enough. And wifi is free and blazingly fast---I did a speed test and got on the order of 100Mbps. (It's also easy to set up wifi from your laptop. You get a piece of paper form the front desk with a username and activation code. Fire up a browser and go to one of the specified networks. Then *don't use the activation code as a password*---instead, follow the written instructions and click on the link to activate the username with the activation code, creating your own password on the way.)
Now for the slightly bad. First, the rooms are getting slightly shabby. It's nothing very objectionable, as they are very clean, but my blanket had some holes worn through, the room-darkening curtains had a bunch of marks on them, the furniture was a bit dinged up, and the towels were all slightly different colors. Second, the breakfast area really doesn't have many places to sit---it's more of a waiting area than an eating area. Again, not ideal, but no big deal. Third, there's a lot of light in the rooms that comes in from under the door. I'm used to sleeping in a very dark room, so I found this made it a bit harder to sleep.
However, all these issues are minor, knocking off one star combined. The major issue is the bed. The bed in the room I got was rock hard, and has to be the most uncomfortable bed I've tried to sleep on for a long time. I think in retrospect I should have tried sleeping on the floor instead, as that may have been softer. In any case, I had a lot of trouble sleeping there once my initial exhaustion from travel wore off. The bed is enough of a problem (and my experience is seemingly consistent with other reviews) that, unless you're used to sleeping on plywood or something similar, I recommend against staying there, despite the other positives.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.