Firstly I love these boots and am curently on my 2nd pair. They are lovely and warm and are completly waterproof from the ankle down, the neoprene tops are showerproof. They have a fleece lined sole which is great if you are like me and spend hours on your feet. They are very comfy to ride in and keep your toes toasty when compared to normal riding boots when your toes go numb when riding out in the winter.
The only downside and I have had 3 pairs that have had the same problem with every pair. The zips on the back of the boots they tend to get jammed especially when they get muddy. Once, jammed they miss teeth and never do up the same again, i.e gaps up the back of the boots. Unfotunatley, I have yet to find someone to repair my zips, as the zip is attatched to the elasticated panels it's a very difficult/ costly repair. If your zip does get jammed don't force the zips, try washing them in hot soapy water and lubricate them with vaseline or similar.
They are pricey but they are a good investment for riding in cold weather, not really suitable for muddy field's!