Lots of good insight there. I realize that this really comes down to which compromises I want to make. I'm leaning heavily towards fulfilling home defense purposes over hunting.
In regards to barrel length, I'm very, very fond of the 18.5" as it simply feels great in my hands and when moving around. My thought is that getting a single 21in barrel is actually yet another huge compromise rather than getting a second barrel dedicated to hunting. I'm not a millionaire by a long shot, but if the M2 platform proves to be as good as most people claim, I would rather spend a good chunk of cash on a 24 or 26in barrel, rather than buying an entirely different gun just for hunting. Not to mention, I've actually seen a few people shooting slugs (rifled and non rifled slugs) out of a smooth bore 18.5in barrel with shockingly good accuracy out to 75-100yds. I'm nearly convinced that the tactical barrel would be adequate for the occasional, casual deer hunt. Haven't personally seen anybody trying to use the 18.5 for turkey or pheasant, but with the proper chokes I don't see why it couldn't be done with some success. So maybe the short barrel would be the smart, most versatile option until I decide if I really want to get serious about hunting. Crazy thinking?
As far as the sights, I never really thought about repeated removal/installation of the ghost ring sights potentially stripping out the threads. Going to have to look into these sight options a bit more.
The straight stock option is a must (preferably the comfort tech), but the inability to add a true hunting barrel later on is a complete deal breaker.
Lots of options to be decided upon, but the BIGGEST problem is actually finding one of these for sale. Seems like every M2 Tactical I find online has the pistol grip or a standard non-ComfortTech stock. I've been on GunBroker, GunsAmerica, and numerous forums and online dealer sites....striking out every time.