I (almost) never make a buying decision based on MIRs. (Mail in Rebates) I am disorganized and forgetful, buy swear that half of my problem getting back rebates is due to the companys offering the rebates. I think I am about 50% on rebates. One time the salesman misrepresented a rebate on a camcorder, another time the retailer said I the product was not eligible even though I saw it in the paper. In all cases I bought the item based on its price before MIR, and didn't care too much.
Also, anyone who thinks a check promised in 6-12 weeks, IF YOU JUMP THROUGH SAID HOOPS, is worth near its face value is a fool.