Bwtweeen the two, agreed. That sub, no offense likely isn't sufficient for those heresys IMO. The heresy IIIs would excel out of the BOX (but are limited in bass extension). You won't need a sub with the Cornwalls and a couple cheap tweaks to them can get them sounding VERY good. Also agree on the room, really depends on if you have the room. I have Cornwall IIs that I'll be keeping. I have had heresy III, Cornwall III and Forte IIIs in here, among others. Cornwalls 8 feet apart and in the corners, on the walls, they are quite impressive. @Dave A has MAHL tweeter sets that sound excellent, as do Crites tweeters/ titanium diaphragms. Little crossover recap and you are good to go. Just my 2 cents.