British-German beer style twins

Same. In my one trip to Dusseldorf I was able to try most of the major large/small brands consecutively and it's night and day. It's almost up there with calling Miller Lite a "true pilsner." I'm not even going after the big brands so much as just noting how incredibly different they are. I can fully understand someone actually preferring them. I suppose those beers and the presence of sticke and doppelsticke probably go a long way to explaining why most American altbier attempts taste nothing like the beers served in the altstadt. Most are based on totally different beers.

Back to the discussion at hand - IMO, the sweeter big market altbiers taste more like English browns than the small batch altbiers. At least to me. The smaller batch ones taste closer to Belgian ambers to me.

 

Would you say that there's a notable difference in hop presence too?

 

Most definitely. The hoppiest tasting beers I've had in Germany (not counting IPA's and such) are the altbiers from Uerige, Fuchshen, Schlussel, Schumacher, and Joh Albrecht. I didn't make it over to Kurzer.
The larger brands like Diebels, Schlosser, Frankenheimer taste distinctly sweet (low attenuation I suppose) and with the hops dialed, way way back. As weird as this sounds, they actually remind me a little of N/A beers with that heavy Grape Nuts note. I like that flavor, mind you, but it's an occasional craving and not something I want a ton of. The minimal hop character shows up as more of a back end bitterness rather than a balancing element.