Purchased these wheels as a bundle with a 105 cassette for my wifes winter bike.
They aren't the lightest wheel for the price, but if you want the perfect combination of weight / build / price, I don't think you can get better.
The build quality is without fault, at least on this pair, they run smooth, true and quietly. But more importantly, the wife is chuffed to bits as "they look really nice in white and match the bike".
The 105 cassette, in combination with a new KMC chain, just gets on with the job.
I opted for the ten speed 11-28 this time. No problems accessing the 28 with the standard derailleur. The gaps in the ratios don't become apparent until you're climbing the really steep stuff. At which point there's usually more pressing things on your mind than ratios.
The RS31 wheels have enhanced the look of my Cannondale and increase the spec and performance. My Strava average speed on my regular route has improved. Highly recommended for the feel good factor and great value.
Great mid-range wheel set for entry level money. They're replacing a set of Mavic CXP22 rims. Can't say i've noticed any difference in acceleration, but they do seem to help maintain a good pace on the flats. Perhaps down to the deeper rims and aero spokes, or maybe just psychological. Stiffness is way superior though, virtually no flex in out the saddle sprinting. The Mavics would rub the crud-catcher when stressed laterally.
Looks wise (if that's important to you...) they're brilliant.
The 105 cassette is 95% dura-ace at 40% cost. All depends what that 5% is worth to you.
Merlin service is, as always, brilliant. Speedy, good comms and well packaged.