I have 3 di ARs and was thinking of dumping one for a piston gun, a Ruger to be precise. How ever last night a came across a never before seen new piston design that does not use a buffer or spring so I can fold a AR stock. Rainer Arms has a combo for $1,400 that has a 5.56 and 300black barrel and oprod that really really has my interest. Anyone shoot/own/ seen one in person before?