>>17659847The main reason I use it, both then and now, is because it has Aromatherapy and Natural Cure, while also being surprisingly bulky.
Giga Drain and Leech Seed let it out-last a whole lot of things, and Sludge Bomb has become really good in X/Y with the introduction of fairies. I also love Leech Seed on it, because I often use it predicting a switch-in to something that can more easily take down Roserade, and now I can more easily switch Roserade out, as whatever I put in to replace it will get healed for some of the damage by Leech Seed. If they don't switch out, then whatever is currently fighting Roserade will have Leech Seed on it instead.
Plus it's a lot of fun to use against baton pass teams, since baton pass will transfer the leech seed.