I also find it to be a bit tougher. The last Pokemon game I played was SoulSilver, and it was way too easy, until Red.
and then the game decite to make you bite the bullet hard. At least you had Vs. oh wait...but you can do match with the vs. seeker all you want, but only in a certain time sadly.
However you could get phone number of gym leader, set the clock to the time of the desire gym leader and keeping battling that gym leader all day long. One call after the next.
It isn't like you have to do much grinding. In gold I typically beat him as soon as I train a ttar and I only do that because I like ttar. Assuming you aren't an awful player high 50s to low 60s are easily enough to beat him. Heck the only time you should possibly need to grind is for the elite four and thats likely not necessary either.
http://www.youtube.com/watch?v=Raiz5MAb98Q Official Salamence of the Pokemon X and Y boards
Actual trainer battles have become harder, due to a greater variety in moves, types and pokemon as well as trainers using items (i believe it didn't exist in gens 1-2). Dungeons and the like are certainly easier IMO.
Official and Original Mountain-Eating Goddamn Aggron of the Black/White Boards LoL IGN (And IGN for almost everything): Rathilal