My 2 Cents... and the quick&easy way
Well, the things actually give shitty EXP (7 points for a turret, crap eh?), but they come with about 600 of the large fusion cells apiece, so you can store up on energy weapon ammo for later in the game, or you can just sell it (I hope the stuff's expensive, didn't compl. mission yet).
And I have found a quick and easy way to blow up the damn things. Took me an hour to blow up first one, I thought "WTF" so I immediately decided to use... a more devious method.
Set combat mode to CTB, get guys within bare 95% range, maybe a BIT less for cover, then set em ALL to aggressive, line em up (don't even need cover if they are crouched) and let em loose. Takes about 4-5 minutes with turret popping up, getting gunned down, going down, then popping up again for a long time before the bastard thing explodes. The turrets ARE true bitches, but if the large fusion cells are worth a lot of scrip I suppose I might start liking them turrets. Only thing I'm scared of is a group of three turrets I see ahead of me. Scaring the shit out of me, the things, I have to put Shotgun Doc behind all my guys and keep healing Farsight coz she soaks up all the damage for some reason.
P.S. the fantasy ball is cool!