Wow, thanks, that is a big help. I really do appreciate the pictures. It is quit a bit smaller, rather more compact, than the Light Tactical. The Light Tactical is great under a DTA HTI .50BMG but I think it's a bit overkill on a Mk20.
I have an Atlas under an SR25 that I don't like for a number of reasons and if the LRA ain't gonna work then I'd rather just have a tricked out Harris. At least it's light and user friendly.
The Ultralight looks like it'll work on these smaller rifles, I'm gonna give it a shot. I do plan on using a tripod later on, but figure I can put that mount closer in or use QD mounts for that and the bipod and swap between the two, which may be better for multiple rifles, only needing the one mount and a spare.
Yeah, judging by the awesome pictures that gigamortis put up (thanks again) I think I got enough to go by to feel comfortable pulling the trigger on the smaller LRA for the Mk20.