Not that I'm particularly qualified, but I'm going to type up my opinions on various and sundry cycling gear. Maybe you can think of these as the impressions of a newbie and that will bring some value to them...
I recently purchased a pair of SKS RaceBlade XL Fenders from Amazon after the recommendation of someone at a Local Bike Shop (BioWheels). (Note: I try not to be evil and try things at stores and then buy them online, but they didn't have any product in this space in stock, so I was forced to go online. Also note, the price has gone up on these since I bought them... I'm not sure why.) These are fairly lightweight plastic fenders which strap on to the fork in front and the seat stays in back and cover a lot, but not all, of your wheels.
This morning I finally had an opportunity to give them a real try in the rain and on wet roads and I have to say, it was a good investment. A previous experience with cycling in the rain led to a huge amount of gravel glued to my legs, back, front and, occasionally, my face along with a huge amount of water shipped into my cycling shoes. I can put up with quite a bit of things, but water in the shoes is very uncomfortable. Interestingly, the rain itself isn't much of an issue when biking, but the rain coming off the road goes straight onto the legs and into the shoes.
This morning, despite wet roads the whole way my legs stayed mostly dry. My shoes got a very light speckling of raindrops, but didn't really ship any water and my socks stayed dry.
The SKS RaceBlade comes in 2 sizes... one for 18-23mm tires and the XL for 23-32mm. I got the larger size, since I'm currently riding with Specialized All Condition Armadillos which are 700x25, and they seem well sized for my frame. Getting them on and off is quite simple... they're basically held on with rubber bands. They came with little bits of tape to protect the frame where they attach, but with ye-olde Panasonic I decided that a few minor scratches wouldn't matter.
The one thing I can't comment on is how well they work with a cycling computer, as I don't currently have one. I think it wouldn't be a problem to get things to work together well, though... I haven't seen a cycling computer that cared about how high or low on the fork it was mounted, so long as it was close enough to the magnet.
Overall: Feet and legs are kept mostly dry when biking in the rain. Light weight. Easy to attach and detach.
