I am not sure I get this comparison, two different price points. GCBC is about 50% more than Divi or most other TS type places, so if you were to add 50% to GCBC would you compare to La Samanna?
I like and have stayed at both, really like GCBC for a few extra nights and we have enjoyed staying at Divi for weeks.
As for friendly staff, of all the places we have stayed the most friendly staff would have to go to Sea Palace. Don't really want to stay there again but from front desk to maids they were the best. Best maids overall I would have to give to The Towers, and best front desk would probably have to go to Les Balcons many years ago but most have been pleasant. Best beach service at a resort was certainly GCBC, but we rarely stay at the resort for the day but if at GCBC we would more often.