As jBSjunk says it's just the maintianance, no different than running a flat tappet. The oiling problems that you speak of donot exist, unless you put oil restrictors in the lifter galleries, which most people do for racing because it keeps oiling down upstairs, where you donot need more than a mist on a full roller motor, that is unless you're running Nascar and you have to keep the valve springs cool and alive for 500 miles.
I'm sure some of the engine builders will come in on this and may have some different opinions.
JMO
Zip.