Commuted for three years into westminster on a bandit, fazer and an xt600. The fazer was a handful to filter fast on, which I sort of became addicted to and would race people doing the same thing. Haven't really done it since I wrote off the xt when a merc decided to do a uturn in front of a bus (100m from my home doh!) at 40mph. Bastard rider behind me said he saw it was my fault as i was riding insanely fast for the conditions, so i had to pay thru my insurance for 4k worth of damage to the merc. I'd managed to do the drivers door, which had been totalled and wouldn't close, then I hit roof and bonnet with my body and bike swung round and did the front wing. It was a 6m old car with a woman driver. She said her son was bragging to his mates the next day as he was in the back seat and said he thought his car had been bombed:)
Lost interest in commuting after that, but still consider it now and again if i could pick up a cheap scooter or another thin bike like the xt. I could get up on to pavements with that and other obstructions. Also got done on the r1 for doing 59mph just before the houses of parliament.