I have owned 2 KLR650s, and sold them both. I love them, but finally had to come to terms with the fact that they are simply not comfortable enough for me on long trips. I still like trail riding, and I bought an XT225 for that, and heavily modified it with just about every bolt on goodie you can get for them except hard panniers. I bought a Goldwing for comfort, but for a solo rider it is overkill, and it gets less mileage than my car. I still have it, but don't ride it that much anymore. My plans are to sell it and buy a Harley. The reason is the Kawasaki Vulcan 750 I bought new back in 2002. It is by far the most comfortable bike I have ever owned, except for the Goldwing, and it's light weight and maneuverability more than make up for that. It is definitely an all day bike. I have put over 74,000 miles on it in 10 years. I have done 2 SS1000s on it, with ease. I will keep it till I wear it out. I test rode all the Japanese maxi scooters recently, with plans to buy one. But I found them very awkward, and harder to handle than the Goldwing. The Silverwing was the best fit, because it has cutouts in the floorboards so you can put you legs straight down beside it without having to hang your feet over the w-i-d-e floorboards of the others. They were so wide that even with a 34" inseam, I had trouble getting my feet on the ground. Even the tall KLR was easier to ride around town. I couldn't flat foot it, but I could tip toe it fairly easily. The edges of the floorboards hurt my legs when I tried to put my feet on the ground on the maxis.
I like scooters, I have 3, a Yamaha Vino 125 and Zuma 125, and a Genuine Stella 2 stroke. They are a lot of fun, but they may as well not have any suspension. I have a bad back, and everytime I hit a bump, which is quite often around here, they pound my back like a jackhammer. Because your feet are out in front of you, it is difficult to raise yourself off the seat when you see a bump coming.
Last thing, I would check into the maintenance requirements. Some maxi scooters have ridiculously high maintenance costs. Especially check the valve adjustment intervals and procedure. I chose the Zuma 125 over the Honda PCX150 because it takes 15 minutes to do the valves on the Zuma, and 3 hours on the PCX. Apparently you have to remove the whole body and pull the motor to get to the valves on a Majesty. Dealer book says 6 hours labor. Not sure about the Burgman. But definitely something to consider.
If comfort is your main concern, you might want to look at a cruiser, although modern cruisers are not as comfortable as the older ones. The Vulcan 750 is a 1985 design. Newer ones are designed more for looks.
I noticed that the new Burgman 400 is only available with ABS, definitely a turn off for me. Most like it, I hate it.