Wish this was an easier call. Myself, I'm a big guy (6'2"/315) so factor that in to what I have to say. I've ridden bikes with 750, 1000, and 1500w direct drives quite a bit. I now ride a 1000+w geared rear hub that I love!
The downside to a gear drive is the fact they kind of poop out and start loosing efficiency at 20mph or so, where the direct drive is just hitting it's stride at 20 (this assuming the speed restrictions have been removed). This may be a factor if the primary purpose of the bike is commuting longer distances for instance. For stop and go city riding, and trail, the gear drive's peppy performance makes it pretty popular.
Riding these different drives has taught me that the gear drive offers much better acceleration from a stop (like crossing a rod for instance), and does much better in hills, even small ones. What surprised me was that if anything, the gear drive offers better mileage. The 1500w direct drive I had would travel an easy 25 miles. When that motor was replaced with a 1000+ watt gear drive (MAC 12t) with no other changes, and ridden in the same area, the bike now makes 35 miles easily. In my case, much peppier, and offering better mileage.
People that talk about noise, or extra maintenance with a gear drive are talking about gear drives with very high mileage. I'm thinking most riders will go years before anything like that is true. In any case, count me in with those that believe the increased performance available with the gear drive is well worth any downside. With about 700 miles on it now, my gear drive makes no more noise than the direct drives did. Just a hum.
As one that rarely rides over 15mph, THIS rider favors a gear driven hub over the direct drive any day. To be fair, if I had to ride the bike 10 miles across level terrain every day to get there, then another to get home, the direct drive might look like a better option. -Al