The more big cooks you do on it, the better it'll get sealed up. Also, there is nothing wrong with cooking @275, you just get done quicker and can spend that time doing other things, or sleeping.
Modded Brinkmann Gourmet. Basic UDS. Rescued 22.5" OTS. SJS Mini-WSM. Stubbs. B&B Oak Lump.
Cannondale 2009 F8 (for burning off all the great BBQ)