It's all subjective in this class of bike, but I 2nd the notion to look closely at the MG V7. It's down a bit on power, but is a more interesting motorcycle to my eyes and has better fit/finish. The small Guzzi v-twin has a lot of character. It's doesn't make a lot of power, but that's not what you're after in this sort of bike.
The kinked-pipe Bonnys have never looked "correct" to my eyes and all look very cheaply built when you see them in the flesh; I'm especially annoyed that they don't even include a tachometer on many models. If I were to get a Bonny, I'd get the blue/white SE with the cast wheels so you get tubeless tires and get rid of those hideous kinked pipes. The Scramblers are pretty cool, but the high pipes dramatically compromise the ability of the bike to accept any kind of accessories or even mount soft bags. The Thurxtons..... I don't know, they just look like they're trying too hard. They cross over into the area of looking like a performance bike and none of the Triumph retro twins are performers.
I wish Kawasaki imported the W800 - this is nicer, better-looking Bonny than the Bonny.
If your not hung up on a twin, by far the most capable retro bike right now is the Honda CB1100. It's a totally different look (much more UJM), but its a good-looking bike. Next year, it is coming with spoked-wheels, twin pipes, silver engine, and some other nice upgrades. And it's available with ABS. But it's a bit more money than the Bonny. And a lot more bike.
If you're not scratching a retro itch and you want some serious performance with your lightweight bike, just get the new Yamaha FZ-09. For $8K, you get a 110-hp at the rear wheel, bag of monkeys handling, and Yamaha reliability. What's not to like? This bike is the bargain of the decade.
Finally, if you just want a lightweight utility bike to toddle around town, I'd look closely at the new Honda 500 twins. You can get these well under $6K with ABS! Long on value and utility, but short on pizazz, they're certainly not likely to get you any hot dates. But they're superb bikes - essentially the CB350's of the 21st century.
Just random thoughts reflecting my biases. This sort of bike is bought with the heart, not the head.
- Mark
