Lots of people say that and to the extent that you don't have a problem with oil bleeding out at full lift it's correct. However those lifters do nothing for oil control in the event of valvetrain failure, and do nothing to corect the lifter bore angles which (sadly) are just as acurately done as all other factory machining.
To me it's the same thing as buying top dollar pistons and running them on the original 70K mile worn factory bore.
If I'm going to pay four figures for the cam, pump drive, and lifters I want all the benefits- not just for it to run. It's not a matter of "will it work". It's a matter of how well will it work in the long run. So personally, I bush the bores. Every time. Period.
If it's not worth doing bushings, and the roller cam choice is a street type roller - I'll run a flat tappet and make the same power for a grand less money.
