thats easy Wildcat Mk3 hands down, Mine could easily make me let go of my Impact Mk2 and Dreamline..
whether on a bench, off a gate post of off hand it runs like silk and is effortless to carry hour after hour,
I actually prefer the safety at the rear -
the only main benefit of an impact has to be the valve adjuster and slug probe kit...so for .30 you might need an impact to get the the speeds you want.
I would suggest you try both to be sure.