ya, they are and thats sorta what they were designed for, added safety for an inbound avy or just out of bounds one....
Only problem is finding one someone with just the RECCO - you need an expensive, bulky and heavy radar sensor, and you relay on ski patrol to hear about your avy, get organized, go out and bring a sensor. I've heard of helicopters being mounted w/ RECCO ground penetrating radar in Europe but if your in North America, in the backcountery, or even really in the sidecountery just a RECCO I think is a really poor idea.
You have really no notion of when or if the ski patrol will show up, or if they will in time to save you from the tramma of a avy, or the suffocation. Being able to find your buddy and dig them out quickly is really what could save their life - or use actual knowledge and practice to avoid high risk situations.
BTW - you really need a Recco in your boots too or your pants at the hemline - that way if your head down they can still find you (as I understand it the radar reflectors can be blocked by your body).