I'm presently on my second year-long tour with a Rohloff and wouldn't consider trying anything else.... well maybe a Pinion P1.18, but that's a whole new frame.
It's not specifically about the 'number' of gears but the ratio between them, with a Rohloff the gears are equally spaced (you'd need to check online to see the ratio), whereas a derailleur system is far from equal, with some higher gears being lower in ratio to the gears beneath it, a derailleur system is not supposed to have every cassette gear used on every chain-ring, the cassette's larger gears are for the small chain ring, middle ones for the middle chain ring and smaller ones for the largest chain-ring, moving the chain over the complete cassette means the 'chain line' is not straight and leads to chain failure.
If it's just small tours around Europe then a derailleur is fine, I chose the hub for my London - Capetown tour and had no problems whatsoever, just remove and clean the chain once in a while (I used a KMC BMX chain) but that can now be a thing of the past with the new Rohloff belt drive bikes.
I'd advise against using a second chain ring on any hub gear, you could easily exceed the maximum torque level and damage the hub, the Rohloff manual states ideal sizes for chain-ring and the rear sprocket, I use a 16 sprocket & 42 tooth chain-ring.
I visited the Rohloff factory last year and met Berni Rohloff. Shimano started making hub gears after seeing the success Rohloff were having, but being Patented to the maximum Shimano have not been able to replicate, and doubt they will for a long time.
So really it's down to the intended use of the bike and money available to spend. I'm sure the Shiamno hubs are okay, but then again so are Sturmy Archer, although now owned by Sun Rims, and made in Taiwan, not England.
http://www.sturmey-archer.com/products/hubs.html
This may prove a good read:
http://en.wikipedia.org/wiki/Bicycle_gearing
mark