Bikes I'm considering: Fazer 600, Hornet 600, Bandit, GT550, Z750 etc etc.
As an ex1200GS pilot who's owned 2 of the bikes on your list, I'll pitch my 2 cents here.
The Bandit is a brilliant bike, but it's for missions. I commuted mine for 4 years and it's deficiencies eventually got to me. The GT's are old hat now, but I put over 100k miles on my old GT750 before it finally threw in the towel. Not exactly frugal, and weight in town can make it a handful in close quarters combat with the traffic.
I'm currently running a '00 Deauville for my 30mile each way commute between rural bliss and Dublin shitty centre.
Deauville's are not without their faults, but are a hugely under rated bike. They'll commute, tour, and - within limits - scratch. Mine gets (ab)used for commuting and running around various city locations, plus the occasional run to/from our Cork office. It's more than capable of embarrassing sporty iron in tight turns with the right pilot (they need commitment) although pegs go down early compared to the Bandit. More to the point it'll run 300+ kilometers on a full tank, and it's easy on the insurance and consumables. They are something of an acquired taste, and most people will tell you they're slow, but they're nowhere near as slow as they feel plus they're all day comfortable at legal(ish) motorway speeds. Mine's about to roll over the clock (klms) and it's been blown over in gales, ridden through floods, fields, building sites and up roads that would bring a tear to the eye of the most ardent Landy fan. It's also done tens of thousands of city miles without complaint. I bought it as a workhorse in the same mould as my old GT750 and didn't expect to like it much if I'm honest, but they do grow on you.
If I was living in town, and didn't have to do long motorway stints every day, I'd probably be running a CB500 for more or less all the same reasons as above and relishing the flickability of what must be one of the best bikes Honda ever built. The power and acceleration of a middleweight with the sort of traffic carving abilities only a 125 can match. I've never got off it without a smile on my face.
Hope some of that helps.