I think Black and White is harder than the past games. I found out one thing that changed. Gaining experience. Let me explain.
In the past, if you fight a Pokemon, you get a fixed number of points per Pokemon per level. Let's say, if you fight a Lv. 6 Pokemon in the past games, you get a set number of points. However in this one, let's say you battle a Lv. 4 Pokemon with your Lv. 5 Starter and get 40 EXP. Later, you fight that same Pokemon at Lv. 4, but your Starter is at Lv. 9, the EXP you gain this time drops. And if you got a Pokemon that takes forever to level up and you don't want to fight it out on the next route with Pokemon at a higher level, you'll be fighting for much longer. ><
Better be happy Nurse Joy doesn't charge you for using the Pokemon Center more often. I had two Pokemon I caught faint at Route 2 at least five times. ><