These will keep your feet dryin my experience for 90 minutes or less, even in Oregon winter rain. Beyond that, water will start leaking in from your legs. They are much easier to put on than anything Ive had with zippers and they work just as well.
I have been riding with these for 3 (Silicon Valley, CA) seasons and they have held up quite well. But, like any other shoe cover, they resist light rainmist, but anything heavier than that and your feet will get wet. They are most definitely NOT waterproof. Water will get into your shoe from below, or will soak through your leggings and run down your legs into your shoes. That being said, for temps down into the low 40F range, or light rain, they function very well. Below the low 40's, you might want to buy something thicker and more thermal.
Reasonably priced P I product, that is light, flexible and durable. I used Gore Gortex rear Velcro'd before (more expensive), but prefer these now. Room for chemical warmer pad over toes outside shoes with good effect.
Most all of the shoe covers I've bought in the past have had a very short life, seems most just don't hold up. These Pearl Izumi's are a refreshing change, fit to size, and durable. I use them on dirt roads with the cross bike or road bike and they have held up better than any other shoe cover I've ever owned.
Very stream-line, totally wind resistant (my feet have never been warmer), don't feel like you are wearing anything extra
A little tricky to put on at first, but after a few times no problems.
My only complaint is that on very wet days, water will eventually start to leak down my leg and my feet get wet (although they are still warm due to the 100% wind resistance). If I could get them to seal on my legs, they would get 5 stars.
I would recommend them to everybody
Overall, I'm very happy with my purchase. I picked these up for two reasons.
1. Wanted a waterproof barrier wet wet riding days. They do very well there as very little water has made its way into my shoes.
2. I needed another layer under my winter bootie. I have used these as the first of two layers when riding in sub zero temps. I went with these as my first layer because I am unable to fit a heavier sock in my cycling shoe. Alone I have used them in the 40-50 F range, but below that, look to something with more insulation.
My only concern would be long term durability. I fear that the bottom could become torn up either by walking or if careful attention is not used when putting them on and removing them.
I've got lots of compliments on these shoe covers. They look great, and seal in your nice, expensive shoes from getting dirty and from letting the cold and rain in. They work great. Anything below 35 and they're cold...for me anyway.