I don't tend to leave and rejoin, but I have been known to. Generally, I just avoid marginal situations with deep stacks, and tend to find other deep stack players also avoid marginal spots with me. I feel that I get more respect for raises and 3bets when I'm sitting there with 300bb, I guess that's psychology, villain thinks I'm good, so I steal and resteal a shit ton vs >100bb'ers and avoid raising junk vs <50bb'ers. Because I find it easier to bully people with a big stack, I prefer to keep my money on the table. It's only if I'm feeling tilted or not on my A-game that I bank my winnings.