I use an Epi UL410s2 and absolutely love it. I'm trying to scrounge the funds to upgrade to the 750. I sold my Berg mini-stack this evening as I have not been using it since getting the Epi cab. I agree that the TFunk\Berg match is not great if you are looking for a nice, full sound - the mids\highs are unbeatable, though IMO. I personally think wider sounding cabs work best with the TFunk - since it is relatively mid-focused, the wider tone helps even things out.
+1.. the Series II 410UL sounds WONDERFUL with the TF. The Berg HS series is way too much 'mids on mid's for my ear with the TF. However, it also sounds good. It really depends on if you are looking for a more old school, tighter, mid punchy tone (Berg HS), or a somewhat more modern pop/funk tone with more true deep lows and a more airy, smooth, sweet top end (410ULII). Both sound great for what they are.
The Whappo Jr. is cool also.... it's wide and deep sounding, but with a very polite and organic top end... so it really sounds more like a REALLY good, more articulate 2x15 cab to my ear.
I've yet to make my TF sound 'bad'... just depends what you want.
Here's an oversimplification:
Will Lee type tone.... Epi410UL (II).. big, even, with some grind and sparkle
Willie Weeks.... Berg HS210/410... tight, punchy, growly but more mid voiced (I have not heard the AE's yet)
Bob Babbit..... Whappo Jr.... big, fat, warm, old school with articulation.
Burk's LDS cabs sound great also, and are closer to the Epi (I) tone to my ear, and I also LOVE the sound of a pair of Aguilar DB112's with the TF... tight, punchy, growly, but with nice low end extension versus the Berg mini stack... really nice!