We stayed at this house on Memorial Day weekend with three families (6 adults, 4 small kids). We stayed for three nights, and thoroughly enjoyed ourselves. The house is not cheap by comparison to other options, but in the end I felt that the location, amount of space, and features made it a good value.
My biggest concern before arriving was the proximity to the highway, and therefore noise, but I mostly found that it wasn't an issue. To be clear: you can definitely hear a low hum of cars driving by at pretty much all hours, but it wasn't loud or disruptive enough that any of us seemed to mind. There are also white noise machines in all of the bedrooms, but we didn't use them.
The neighborhood is very upscale - Montecito is definitely one of the nicest neighborhoods in Santa Barbara, and the house fits in pretty well with the area. It's a 5-10 minute walk down to the beach, which is a narrow strip of sand (maybe 50 feet wide) between the water and a sea wall. It was a little chilly in the water in May, but not too bad. If you leave the house an go north (away from the water), there's a small business district just a few hundred yards away with some restaurants and shops. The nearest supermarket is a 15-20 minute walk (or a very short drive).
The house itself is in really well-restored condition. It's an Eichler, so there is tons of natural light, and lots of open space. The bedrooms were all decently-sized, and the beds are comfy. The kitchen is really pretty excellent. New, high-end appliances, and very well-stocked with equipment. We used the gas grill in the yard, and the hot tub, and everything was in great shape and working order.
The process of reserving the house, signing the contract, paying for the deposit and later having it returned was all very seamless. I remember thinking that the deposit was really expensive ($2k for 3 days), but they have a nice house on their hands, and I guess that's life.
I would highly recommend this house to anyone who's trying to get a decently large group together, and who wants to be walking-distance from the beach.