Yes, it would be a good investment. The stock HD800 is very different from stock LCD2 (any version).
i have been a bit reckless here i guess. reading reviews and comparisons i should not like the hd800 stock. (filtered, who knows?) never auditioned one either. but there are 2 sets of ears on here i trust (Ian's and Frans') . this opportunity came up, my lcd2 had been sat in a drawer for months and i thought "what the hell", i have a Kameleon, filters are cheap and delivered quickly. will find out soon enough , if the gamble paid off.