I have flown with some recently qualified PPL's who have demonstrated far more aptitude and airmanship than other pilots with 1000 hrs+.
Although a good check-out should be made to prove the new pilots capabilities I think it is just as important that personalities don't clash in the group.
One question, why are there so many unfulfilled groups out there? Is it the economy, lack of new pilots, more people buying on their own or just too many planes out there now?
To summarise, if I was in a group I would have no reservations whatsoever to a new PPL entering as long as we got along well and he could handle the plane competently.