My friend who didnt understand the basic principle of poker bought for 200 $ on Party Poker and played .5/1 tables. He also doubled his bankroll in few hours but I was gasping of horror seeing how he was playing.
It was luck really.
Feeling confident he tried 1/2 tables and lost everything in few hours.
I have 600 $ in my BR and I still play
Pokerstars 0.10/0.25 NL tables
Or course there is a difference if you are playing Limit
Just know that :
Player playing UNDER his "confort" limit has tendency to play more loose and be more aggressive
Player playing OVER his "confort" limit has tendency to play more tight and be less aggressive
Now its your job to find what is your confortable limit