Recco avalanche rescue reflector

Here is a news report on a rescue training exercise carried out in the Wildschönau. It is written in German, but you can shade 3 lines, right click, translate with Bing. It gives a flavour of the rescue routines, over an actual avalanche area. (created for the purpose, probably with explosives)
If you scroll down, there is a video. The main things to observe are the coverage methodology, early use of Recco, use of rescue dogs.

We have rescue dogs in our Wildschönau village, and because I train Guide dogs, this is of particular interest. One of our dogs turned out to be blind, and while she was dropped from the Guide Dog training programme at an early stage, she went on to assist autistic children, and then was used for medical condition identification ~ predominantly identifying cancers from blood/urine samples by scent.

Again the video commentry is in german, but you can see what is happening.
http://www.wildschoenau.tv/2013/01/13/bergretter-probten-schatzberg-den-ernstfall/

I think it would be a bonus if your jacket has it but not worth paying extra for.

Don't worry too much about this recco thing. It's a gimmick that is only efficient in the circumstances where avalanches don't usually happen. Another thing with Recco is that it's usually built into a jacket or a ski-boot, whereas in avalanche the victim is very likely to lose both. So while it may give a resort piste skier some additional peace of mind, objectively it's useless in the backcountry. The most important thing is that your son knows how to use the trasceiever and that's what he needs to have on him in avalanche terrain.