well, this guy ( http://www.youtube.com/user/lvl8hack.../1/nqeF5mSmq98 ) has my res setup ( more or less ) so im confident its ok

so here is another question ... is it worth it to work on a draining valve ( especially if i plan to drain only every 3-4 months to replace coolant ) ?
i mean - i dont exactly understand the closed loop thing, but it seems like you can disconnect a pipe, and only when you open the fill port the air gets in and the water drop, so its almost no spillage ?
the reason im asking, is that although i really fancy some sort of drain mechanism that i cant find, i dont know if its actually worth the trouble...