I just did a quick count in my head and I have 5 bikes I actually ride. Just like Cycco, none of my bikes are really mediocre except maybe my Trek 7000 that I bought used on eBay for $150.

Rim wear? I never gave it a thought.

Weight? With my boat anchor laptop or my Kryptonite NY Fahgeddaboudit U-lock, it doesn't matter if I start at 20 or 25 pounds, I'm way over that. Include that extra 20 pounds around my middle...

But for commuting I'll just say that I see a whopping 5 minute difference in a 10 mile commute between my Trek 7000 fixed fork MTB w/ slicks and my Kuota Kredo carbon road bike with 700x23 GP4000 tires. That 10 mile commute takes me an hour, give or take a few minutes, and it is all about the traffic lights.

All said though, on weekends for rides, even in the park, I go carbon almost every time. There's something about the feel of a 16 pound road bike with 1450 gram lightweight wheels and tires pumped to 120 psi. I'll ride my Trek all week and get on my Kuota on the weekend and remember why I bought it.