I have tested so many boots and my choice over any other is the Solite brand. Tall or short, thin or thick these are the best and lightest neoprene boots I have found. I try to ride without boots as often as I can but it gets too cold to ride without them. The Solite 3mm and 5mm boots are the best option in the winters and spring of Bellingham WA where water temps get around 48 or 49 F in the winter.
These boots can be heated (see Solites Instructions) to custom mold to your feet. I didn't think this would make much difference until I tested it. I rode the boots for about 10 sessions before the heat treatment. The size was tight and was bothering my toenails but after the heat molding they fit my feet like no other boots. The fit is tight and does not allow excess water inside. The 5mm thickness (using the included socks) are warm in the winter. I can easily ride the 3mm in the coldest days too.