Lifter Technology Selection

my comment depends on the duration,
and for the FT lifter diameter and base circle
for the roller --roller diameter, base circle, and flat or inverse flank roller
so "it depends"
http://rehermorrison.com/tech-talk-43-the-trouble-with-flat-tappets/
if you look at most any cam catalog a .904 profile shows better at moderate duration than the catalog HR - hard to tell on a solid roller due to the lash - without a cam doc
an inverse radius profile can match the solid FT at moderate duration and exceed at longer durations
a mushroom lifter well the mushroom lifter General Kenetics at first out performed the solid roller in the AMC motor
hardface FT cam can work better than a roller in an Early Hemi but costs more than the roller
both approaches then go to larger tunnels and base circles
it's side thrust that limits how quick a roller can come off the seat and lifter diamater that limits the FT
on the comments above I do not see a "roller getting the valve open to a usable lift sooner" on a lift limited application
now without a lift rule and modern cylinder heads that flow at higher lifts the roller would be the way to go
It's more complicated than just the cam as the valve job changes - especially if you have to stretch the duration out and then kill the low lift flow in the valve job (sinking the valves, steeper seats, etc)
Today's roller lifters can give years of trouble free miles is one point
They can live with fuel dilution
they have less friction