The 200 -> 400 jump

[Flintoff]

Only 18K hands into my NL career but winning over 8BB so far. Obviously this means little and I could be break even for all I know (in fact according to some I am a losing player who has got lucky) but my post is about shot taking.

I am certainly bankrolled for 400NL if I wish to take a shot and many of the higher stakes players seem to advocate putting aside a small amount and taking the occasional risk in order to move up a level.

However, I have heard from a couple of people say that the 200 to 400 jump is considered to be one of the hardest jumps to make in poker.

Is there anything in particular to look out for. I imagine there is much more 3 betting, air c/r's, value bets etc. Anyone with any more useful advice other than table selection (which I do quite well).

Thanks