omg I voted no but I used Roserade :[
Well I used Roserade in Platinum for a while and it worked pretty well. The problem with Grass-types is that they're very weak against many other types such as Fire, Ice, Bug (which is usually nullified with grass/poison hybrids or grass/flying hybrids) and Flying. The main reason anyone would have a grass type Pokemon in their team would be to combat Water/Ground types, but they don't appear too often, so I don't really use grass-types.