Totally agree with the Robs (DeStefano and Green) on HMPE strings on ASLs (aka Hill-style longbows). I have a couple of Howard Hills, a JD Berry Northstar, a Big River, and a couple of Jerry Hills. Some had Dacron strings when I got them, some had HMPE. On every one of these bows, I greatly prefer a HMPE string. On every one of my ASLs, the HMPE string reduces handshock and is quieter (the HMPE has a higher-pitched tone, but overall it's quieter). On my Hill Big 5 (an older Craig Ekin bow), the bow went from being a great shooter with Dacron (very little handshock and quiet) to even better (virtually no handshock, even quieter). An on bows that have significantly more handshock with Dacron (e.g., the Jerry Hills), the HMPE makes a huge difference-- the handshock becomes a pleasant "thump" and they're quieter. Some people dismiss Jerry Hills, but I love shooting them with HMPE strings. My Jerry Hill Wildcat (I think I got it from Rob Green-- he had tip overlays and an HMPE string put on it) is now one of my favorite shooters.
For anyone thinking about getting rid of a Hill-style longbow because of issues with handshock and shootability-- if you're shooting the bow with a Dacron string, do yourself a big favor and try an HMPE string (should probably go with Dacron-padded loops) before you get rid of it. You may end up loving the bow.