Tyres, 23-25-28mm?

furiousox

Just wondering what are the pros and cons of the various tyre widths?
I'm currently on the 23mm Conti GP4000s which I find to be really good.
If the road is very wet I do feel that I'm on a bit of a knife edge as the tyre is so narrow (especially when descending, but I know that's probably more to do with me than the tyre)

Is there a marked difference between a 23 and 25mm tyre, more grip perhaps?
A 28mm tyre sounds huge compared to a 23 but I've only ever used 23's so don't know what they're like.
I take it you would run each tyre type with different psi's but what other differences can I expect, rolling resistance etc?
I don't do any racing btw, just training and sportives.
What are you using and why?
Thanks.

Lumen

I recently switched from 23mm@100psi to to 28mm@80psi, and was surprised that the ride quality wasn't greatly improved. Sure, it makes a bit of a difference, but a pothole still feels like a pothole and the buzz from coarsely chipped road surfaces still comes through.

I also don't think width makes much difference to wet grip.

markcroninbsc

I've always used 23's so im not sure about the 28's but ive used contenental attack/force before and i found them absolute ****e in the wet same thing with the michelin prorace. i now use vredestein and find that these are great in the wet. http://www.chainreactioncycles.com/Models.aspx?ModelID=47705
if its wet and doesnt look like dryin up i just knock them down from around the 110psi to 95 or 100 and they dont feel a bit slippy. (im a bit of a cautious decender tho so im never goin too quick into the corners to properly give them a test)

BostonB

Perhaps the compound makes more of a difference then width for grip.