My Roubaix came with a 10 speed 12-30 cassette. I've been thinking of changing it out since most of my local roads are F-L-A-T. I got an instant case of upgraditis and started looking at 11-25 or 11-28, thinking, I wanna go fast! But as I started looking into the individual gears, what I had, and what gears I actually USE, it became clear that I don't need an 11T, I need a 16T! I haven't pulled the trigger yet, but I think I will ultimately go with a 12-28. I will only be giving up the one low gear, but gaining that 16T mid-range gear which I will definitely put to good use.