In theory the in-lines are supposed to have better ignition. I have had a friend who has problems with fouling crud blocking the channel so after 5 or 6 shots he has to do a major cleaning. The other problem with in-lines is the fact you are stuck with conicals as bullet selection. The twist is too fast for round ball. Depends on what you want to do with it. Don't believe the commercials about high power rifle performance . . . it aint going to happen.
The bolt action is a marketing gimick for the Savage and Remington folks trying to get you to spend big bucks on a "model 700" inline rifle. The bolt will in no way effect accuracy or reliability. It touches nothing important.
Try and find some friend to shoot different types of ML guns before you decide which one to buy. Don't rule out the "Hawken" sidelock types. Good value to be had and they are oftem mor reliable than in-lines.