If I had a Discovery (PCP) that I were fond of, then a springer would be a logical choice as a second hunter, back up, or otherwise. The Diana 34 would be an excellent choice, particularly in .22 cal. As for the "Compact" -- I don't have that air rifle (or a Disco) but I do have a custom-tuned Diana 34 Panther, and it is a fine air rifle. Other considerations? Well, if you already have the infrastructure for PCP shooting, you could certainly consider something like the Air Force Talon or one of the other Air Force PCP's. Other "short list" springers? Beeman R9 .20 cal. Mike Melick-tuned B-26 .22 cal. Or perhaps a Benjiman multipumper.