the rate at which you feel restriction depends on you and what size band you have. the bigger bands are going to take longer to fill. lap band has more than one size. there is a 4cc, 10cc, and 14cc. realize band can hold up to 9cc's.
everyone feels restriction differently. two people with the same size band can get a fill of the exact amount and one could feel too tight and the other not tight enough.
surgeons judge what size of band to use by what size you are. what brand they chose generally depends on which one they prefer. just make sure it is an FDA approved band that you are getting if you live in the U.S. and have your surgery some place other than the states.