I am moving soon to NL25 also (My BR like your and i wait to reach 1k$ mark.). I play currently NL16 and i don't see much difference between NL10 and NL16 but i think at NL25 the game gets harder. Well there still are many fishes at NL25 and i am table selecting a lot. So if there are no huge fish at the table i just left it. At NL16 i can always have 6 tables with fishes on it so i hope i will find so many of them also at NL25.
Also i noticed funny stuff here that happened also to me. If you consider your win$/hour you earned more at NL10 than you are at NL25. I know we don't care about money at this level and we want just to improve our game, but this fact is always funny to me.
Good luck and i wish you reach NL50 soon. Well done.