So I dont know if you remember me saying that the 7520 bass has the most resolution around its price. Well the pro can rival it but the 3.2 is already close. The pro is tighter and faster without the same midbass hump. The mids on the Pro are ill effected by the bass. The soundstage and better imaging helps its focus. But for bass heavy music the 7520 (from memory now) may have the same thump but I find the better. If you prefer the bass qty of the Spirit Pro over the 7520 then the MD pro may be a little much for you cause it def has more than the Spirit Pro.
Thanks for helping me navigate this. The 7520 indeed has excellent bass. But I agree about the midbass hump, and that is what I found unforgiveable... I actually love good bass. I love slam and thump and detail. But I hate bleed and bloat. Some albums can handle that kind of thing, but it just makes a mess of classical strings. I don't mind more bass than the FSP...as long as everything is well delineated. I'm tempted to try the Mad Dog Pro.