I buy the half up or down, it pays off tremendously in NFL, no brainer IMO (3.5 to 3, 7.5 to 7, 6.5 to 7, 13.5 to 14, etc....)
I don't buy from 3 to 2.5 tho, and juice isn't bad at all, has saved me losing quite a bit and I'll take a tie over a loss any day