I think Swift Solo is the Dolomite Man on this forum.
I took it easy - my average speed is a closely guarded secret - so it wasn't that bad. But I had a day of rest before and after. The OP is talking about 9000 m in 3 days. That third day is going to be tough (and the second, too). Not undoable, but tough.4500 m in one day --- eh gads. I did a century with 8000 (~ 2650 m) feet of climbing once and sure didn't feel lie doing much the next day.
I took it easy - my average speed is a closely guarded secret - so it wasn't that bad. But I had a day of rest before and after. The OP is talking about 9000 m in 3 days. That third day is going to be tough (and the second, too). Not undoable, but tough.
The website is strange, that's for sure.The second day takes in much of the maratona plus tre croci--much like stage 14 of the Giro. That includes passo's sella, gardena, campolongo, giau, plus tre croci and is only missing pordoi and falzarego. Passo giau alone is pretty brutal in this direction.
This tour is counting on bussing the few who make it to auronzo back to Feltre to pick up there luggage. Wiggins might make it--you know--if he decides to join the ride.
The notion that this route takes in "all of the best bits" falls short by 90%.
I'm thinking this may be advertising.
Having ridden a fair bit in the alps and dolomites, a few things worth mentioning.
As has been said, those are big days and back to back.
In most tours like this, there are very limited sag seats, so if you're not up to it, it's cold and raining/snowing or you're sick, you could very well still have to complete the ride from hotel to hotel. No options except calling a cab.
Jet lag will kick your butt. It's one thing to get up the day after the flight and go sight seeing, it's another altogether to convince your body that it can perform well at what it considers 3am. I was a competitive athlete in another life and I always gave my body a week to adjust before European competitions. As a recreational rider, I still go over 3-4 days early so I can hang out and do a little local riding before going big. Not to mention if the airlines lose your bike for a couple of days which isn't unusual.
My preferred method is to pick a hotel base camp and ride out of it for a few days and then move on. That way, you can tailor your rides to the weather and what you feel like. Usually with a group of friends, we'll rent a van and do our own thing.
If you want to go that route, I can give you some good contacts.