IMO, rollers are over priced and over marketed ( Gods gift to performance ). For all out high end race engines, yes - other wise, they are just a bragging crutch. The additional weight you have to deal with offsets other advantages below .650 lift IMO. I have run a flat tappet cam with well over .600 lift for going on 4 years now ( using Royal Purple full synthetic BTW ) with zero problems. The larger .904 lifters used in Mopar motors is a real advantage for running aggressive flat tappet cam profiles also.