Erm, putting my opinion forward on the matter, i can kind of see where Maxon is coming from by saying its not a "wacky High school comedy" as following the main story novels it leaves the whole high school comedy around the "End of Day by Day" novels, or as that may not mean much to some, at the time of The Second Raid. Full Metal Panic! leaves the comedy side of things basically altogether after the the novel following that part ends(A Dancing Very Merry Christmas), and becomes its sticks more to a mix of Romance, action and, quite obviously, Mecha. However! its safe to say in other respects that what you saw in FUMOFFU fits the description of high school comedy, and parts of the original series as well, though not as much for obvious reasons. Personally i can't see much of a comparison between Haruhi and FMP comedy wise even in both Light Novel series, bar that of both having high school scenes. Also i will admit not having seen Gun X Sword, but there we go. Keep in mind the FMP franchise is based off of novels, and not a straight to anime thing ;p