I'm looking to replace my worn out 700x28 Specialized All Condition Armadilos on my Sirrus Elite. Was just wondering whether to go for 25c or 23c? I only use my bike for commuting approx 9 miles each way theough London's crappy roads. what are the pros and cons of each tyre size, i.e. would I sacrifice a lot of comfort, by choosing 23c against 25c or 28c and vice versa, would i sacrifice much speed by choosing 28c against 25c or 23c? Logic would seem to suggest 25c to be a good balance btw, i'm thinking of getting Schwalbe Stelvio Plus... as I hate getting P's! Thanks for any advice!