problem with discs like the panther, stingray, cobra, storm, etc. is that i do not consider them midranges as they are really old-school drivers. discs like the roc, shark, buzz etc, were designed to be midranges. the big setback of midranges vs. putters and super overstable drivers are that midranges have a tendency to "hang" and over-carry. old school drivers, especially understable ones, will have a greater tendency for this. a slow flying cyclone/gazelle generation driver is usually easier to fly more consistently in the tweener midrange/driver ranges because they are much more predictable finishers
the big diff in small diameter vs. large diameter is that larger diameter discs take more force to get them spinning. my favorite of the small diameter midranges was always the MRV, as i found it to be more high speed stable than the rest. this just got discontinued and i know at the shop they are clearing them out at $4.79/$5.49/$7.79 for D/X/Z.
there's only a handful of midranges i will stamp my "seal of approval" on because i believe throwing them well is indicative of good form. rocs are like teebirds in the sense that, while everyone can throw them, it is the bigger arms that show just how their flight characteristics differ from the rest of the pack. i've seen people throw rocs 450' without flipping them over, and aside from the wasp, mrv, and sentinel, i've never really seen another disc in that class that can handle that.