Most stocks for ar rifles suck at a bench, because they won’t ride a bag with a shit. A handy carbine will be a less than ideal bench gun and a bench gun will be a less than handy carbine. I have magpul prs stocks on a few rifles. They are my choice. The Luth is lighter, but the adjustments are not really user friendly (by comparison) and the stock has an overall less sturdy appearance. I don’t have any experience with the xlr, but it is lighter than the prs by a fair margin. Also cheaper, given that it comes with the tube and hardware. I may go this route on a build I have in the works...