Just to put it in context, there are a HUGE variety of new Bonnevilles and variants with innumerable modifications; sorta like classic Commandos!
One thing about them is that you can jump on, push a button and out-perform the typical classic Commando, for less money.
Another thing about them, is that it doesn't FEEL like you are out-performing a typical classic Commando, because they are modern, quiet bikes.
If you spend as much on a decent used Thruxon, as you would on a decent used Commando, to turn it into a performer, you would then BLOW AWAY the typical Commando. I'm not talking about a FullAuto head, rods, pistons, etc., just equivalent pipes, springs and intake mods. You still might not be able to touch hobot & peel, but you could give it a go just for fun.
My advice to someone wanting to buy a used Thruxton is to start with one that's mostly stock, simply remove the top yoke, and install the clip ons ABOVE it. Turns it into a totally different bike. (plain Bonnies are almost always better deals, and haven't been thrashed as hard)