Well I'm mostly going by what many users on the volty forums and other enthusiast sites have recommended for this particular bike. Apparently it can handle it quite well and cruising is a lot more enjoyable.
I understand there will be less acceleration but that's apparently not too big of a deal, and honestly I'd be glad if the first gear was even a bit more useful. A few people went the whole hog and replaced the rear-sprocket too, but that was a bit overkill according to most.