B&M - leaving when WAY up

[Big Sissy]

You're at a 4/8 table full-kill table. For the first two hours, you find the table to be very tight; you can actually raise folks off hands. An hour ago, a LAG sat down and has won a number of large pots by calling PF with crap (63o and such). This has completely changed the dynamics of the table. Some players are steaming with the intent of seeking revenge on the LAG, others are just convinced they can also play crap and win.

You run hot for the next 30 minutes and are now up $250.

Even though the table is extremely +EV, it is also extremely high variance.

Should you now leave and take your win at the high-end of the variance, or do you stay and risk what you've won for even greater gains?