I personally don't like the trigger on the B. I do like the twist grip on the Merc and it is lower profile and more positive to use for me.

As for gearing range it isn't quite as limited as you might think. The bike is pretty light so I find I don't need a super low gear. The small tires climb quite well. The crank feels shorter so I can spin out in top gear easier. My Merc gets me pretty close to 300% which is better than a Nexus 7spd internal hub. I reckon the gear range is pretty good overall. Not great for blasting down a steep hill but it is low enough to climb well and I can cruise pretty fast on the flats. All in all it works much better than I thought it would.

As for gbouchar comments regarding repairing SA hubs, they tend to last a long time with minimal maintenance. I have yet to have any issues with any internal hub I've bought. Look at all the SRAM 3X7's on the road and they've had no issues that I've seen. Internal hubs just aren't as popular in the US and Canada as they are in Europe. For a commuter bike it is far and away my preference.