Paul
I agree that unles you are in CAS with a full service you are only getting "some help" from ATC. Therefore I don't think anyone gettting a 'basic service' from ATC thinks that is their prime source of avoidance information - that is still Mk1 Eyeball. But, surely, any help is valuable.
Personally, I do find it useful to get additional information from ATC. Sometimes the warning can be far enough out to make changing course worthwhile. Not for every single aircraft, obviously, but when ATC tell me "multiple contacts manouvering, on your track, +15miles, intermitent radar returns, they might be gliders" then it is ususally no trouble for me to alter course and not fly into that space. If I get one machine ahead, I think it slightly increases the chances of finding it visually if you have a clue of direction / distance.
And I have one experience (fortunately only one) where the tone of ATC communication helped me to decide that although they cannot direct aircraft to turn, it would be a darned good idea to follow the "suggested" course of action rather than to follow the strict Rules of the Air, which would have kept me going straight and level. On that occasion, at least the other chap was squaking 7000 Mode C and therefore ATC could see him.
finally, I don't see that the SSR will be overwhelmed if everyone in the air had a transponder; but it would be interesting to hear from a controller.
Last edited by John R81; 28th Jun 2013 at 12:21.