For years I just got any weed the dealer had. Now I know what strain I am smoking all the time is better I suppose as it is nice to compare different strains and stuff, if you know the strain you are usually smoking quality as well.
I would be subtle about it. When you are getting your bud just ask what strain it is, he probably doesn't know and will bull shit you. But if you act if you know what you are talking about chances are he will ask the next time he gets his stuff of his dealer and he might start getting some better stuff in if you enquire about a certain strain.