I presume you mean that the 115he goes lower. I saw a comment on another thread that it has a tight low-end response, which is basically what you're saying. And that sounds good – at least in theory. I'd like a cabinet with an equally punchy low- and mid-response – not too boomy and not too mid-forward. There is a Guitar Center an hour north and south of me; I should see if either location has one or both of these cabinets on the floor. But it's difficult for me to carve out enough time for such a trip lately. And the only way to know for sure whether either cabinet would sound good in my space... is to try them out in my space.
On paper the two cabinets don't look that different. I've seen a lot of comments in different threads about how similar the two HE's are, but also a number of comments about how the 115 has a bigger bottom end and/or the 210 is tuned higher. A 112 might be a nice compromise – but then perhaps the 112av, as the 112hlf rolls off much sooner than the 210he (again, on paper). I assume that the Portaflex cabinets are a better match for the pf-50t, but I really like the way the AVs sound in the AmpegTV demo of the 112av and 212av played through the V-4B and haven't heard any demos that show off the 112hlf nearly that well. And I especially like the demo by Musikmachen.de playing both the 112av and 212av through a V-4B. That sound! Only the 112 was mic'd, (I digress) but is it really possible to run an 8 ohm and 4 ohm cabinets simultaneously through a V-4B?
As a relatively low-powered 110, the GK MB110 is perfectly fine for practice; it gets the job done. But I find the overall sound to be mid-forward almost to a fault. 7UP comes to mind: Crisp and clean – no caffeine

Switching to flats helped somewhat. But I recently came to the conclusion that in order to get the sound I'm after... well, as they say: You can't get there from here, you've got start from somewhere else.