Moving up to any level means an increase in the skill level of your opponents. Going from nl 100 to nl 200 is not as big a jump in terms of difficulty as from nl 200 to nl 400, but it is still a jump. If you have been beating the nl 100 tables consistently for a long time then you can beat the 200 tables. You should have at least 4k in your roll, preferably 5k. The bigger your roll the less damaging to your confidence stacking off a couple of times will be. Believe me, the first time you lose two buy ins at nl 200 itll suck a lot more than 2 buy ins at nl 100 (duh mr obvious).

But if you do decide to jump you should already be dominating nl 100, and ease into the nl 200 tables. What I mean is if you quad table nl 100, then pick a nice, easy time when there are a lot of casual players (sunday evening?) and play one table. I think youll find that youll get the handle of it very easily.

The main thing is, make sure you are bankrolled. As I said earlier, I would never play without 25 buy ins. IMO. Good Luck.