I have. Looked at several reviews comparing the major offerings. The KTM is supposed to be uncomfortable on long hauls, only marginally more uncomfortable than the BMW (and I was giving the Beemer a serious look because of how quiet they are). The Yamaha Super Tenere was on my list too, but didn't quite stack up to the Honda, which came out ahead on long-distance, balance and responsiveness.
I must say, having ridden the Africa, it is remarkable. There's almost no point putting it in 5th gear in the city - it's almost down to idle rpm in 4th gear at 60km/h. It just chugs in higher gear and if you're just cruising along at 60km/h you'd consider throwing it up a cog but 4th is best when dealing in traffic. It gets to 60km/h much quicker than expected, from Norm Frasers in Newcastle to Bridges Rd it's only a few hundred metres. and a gentle take-off saw me exceeding the speed limit before I was halfway to the intersection.
The Ducati looks more spectacular than the Honda. We saw them side-by-side, the Duke has a more "muscly" appearance, kind of like the difference between a Holden HQ Monaro and a Ford XA 2-door. It's also a Ducati - I've never owned one, have heard lots of good things about them ... but that price tag is sitting there, and I really wouldn't mind being on the road on 2 wheels again.
When I get the bike, no matter which one it is, I'll be modifying it. None of them come with enough light for country riding so I'll be putting HIDs on. I want panniers - already on the Multistrada Tourer but additional for the others. I put a pair of HIDs on my wife's car because I occasionally drive it into Newy - you get both the white spread of light close up like a LED light bar as well as the depth of halogens. I've seen LEDs on a motorcycle (one of the Super Tenere reviews) and they weren't that impressive for distance. I'll go HID thanks. And if I go the Africa, it won't be the DCT model (which doesn't require you to change gears, the bike does it for you). I'll have the full manual, so if I need to clutch-start, I can.
I'll have to dig out the photos - I used to do a lot of touring on a 1977 CB900 FZ Bol D'Or. While this was a good solid bike, it suffered from direct-mounted engine which caused the entire frame to vibrate with the motor. I had the engine blueprinted, balanced and all innards replaced (all chains, pistons, rings, bearings, the lot) and it still didn't help. Unfortunately this was most noticeable in the passenger footpegs. Usual load was a tent, a gas stove, a large tarp to use as an annex, two folding chairs, two sleeping bags, air mattress plus food and drink for a couple of days. If I had no passenger, I'd also carry a guitar and a slab of something noxious.