I have a Wee and bought a 1250S Bandit with full Givi luggage a little while ago.
The 1250 has loads of torque, but it's not an elbow-snapper in acceleration. It is fast - 3.5 secs 0-60mph from memory, but not WTF! like a big sportsbike. It will easily hit 140+kmh on an 80kmh top-gear pass in seconds, so you do need to keep an eye on the speed when overtaking. The engine is smooth and it will pull from 1500rpm and cruise happily in 4/5/6th at 2250rpm around town, but there are some vibes and the gearbox is clunky. I haven't had an inline four for a few years and I'd forgotten how busy the engines sound at a 120kmh cruise - around 4000rpm. The EFI is very smooth and it is easy to ride at legal urban and highway speeds without constantly having the speed creeping up, it is very quiet with the standard exhaust and has a surprisingly comfortable riding position. (It may be a bit cramped if you are over 6 foot.) The wind blast from the standard screen hits me right in the upper body and the chin vent on my helmet, which makes it very cold and wet to ride in winter and I have a Givi touring screen on the way. I put 1" risers, EB PC8 fusebox, heated grips and a set of Wee handguards on mine and will change the standard bars soon for something the same height but slightly wider and with a little less pull-back. The rider's seat is as hard as a rock, mirrors pretty useless, the rear shock is oversprung for my (light) weight, and my petite 5'2"" tall daughter finds the pillion pegs a touch high, but the seat is comfortable. Lights are good, but not in the same league as the Wee.
The immense low down torque means it handles two up without noticing even on the very steep roads around here, and it gets good fuel economy though the fuel warning bars are useless, flashing reserve at about 230k with about 5 litres left. My guess is that it would do around 320km to a tank with perhaps 20km left. The 19L tank is a PITA compared to the Wee, as I'm refilling it a couple of times a week. It is light to push around the garage, seat height is low and it is light on the move. It handles very well if you lean in and power it around corners, but in twisties it doesn't flick as well as Wee, and I can make faster time over the same twisty roads on the Wee. It does not like cornering hard on a trailing throttle. Brakes are good, but there's a lot of forward weight transfer with a pillion on the back. (It's hard for a passenger to brace their legs on those high footpegs.) There is effectively no underseat storage, even the tool kit is a tight fit.
I like the bike a lot, put about 500km a week on it and am glad I bought it, but apart from the Bandit's sheer power, for pottering around on and touring up to a 120kmh cruise the Wee is a lot nicer bike to ride. I bought the Bandit for fast interstate trips where I felt the Wee would be a bit underpowered, but after putting a few thousand km on the 1250, now I'd probably take the Wee anyway for the sheer comfort and forgo the ability to nail the throttle for quick overtaking.
