Spitfires... I'm a fixed blade kinda guy myself, but many people seem to have good experiences with them from what I hear... but that's just heresay...

Grunt calls... take your pick they all do their thing about the same. The key with these is that if you take the time to learn the vocalizations and the proper timing(rut, pre and post rut, morning, noon evening... buck, young buck, mature buck, dominant buck, doe, young doe, doe in estrus.... I think I may have scratched the surface), unless you get the timing right witht he right vocalization, just use it to stop deer that are on the move.... if you've gotta deer hung up out of range and headed another direction, it could help divert their attention.... I use 'em to stop deer for the shot, myself and typically dont use one otherwise....

Rattling... see my comment about grunts.... timing with the rut is EVERYTHING, Rattling with the wrong intensity(like previously mentioned by someone else) a the wrong time in the rut cycle will hurt also. Buck to doe ratios are important too... closer to 1:1 the better, which is likely not the case for where most of us hunt.