I love my Birks, but not as a walking shoe, especially in the summer. But I have a problem with them because I just get sweaty feet. So sorry if that's TMI

but it's unfotunately true. My birks were soaked in a good ole Texas rain many times and they did recover but they were never quite the same afterward, but I didn't know about cork sealant in college. I have to second the break them in well if you do decide to get them, because the thing that hurts is your arch as the footbed conforms to your feet. You will get sore arches in the beginning. Because of this, Birks will not be as comfortable out of the box as some other preformed, supportive sandles.
I have always tended towards Tevas for my walking, summer sandal. I am currently contemplating getting the latest and greatest award winning version, but right now I can't remember the name, however I believe it is the sandle that is on the Teva home page now. The key feature that I am interested in is the new sole design which has fine mesh pockets to allow water to escape through the sole without letting gunk in. It also is has a unique strapping system that goes around (that is under your arch and through the sole of the shoe) your foot to really secure the shoe. This is something that I really need with my, um, problem, as I believe it will aid me in my slippage that tends to otherwise occur. My problem is they surely aren't cheap, and I am hoping to find a discount code for them somehow.
That said, I have hiked in regular run of the mill Tevas and it has been fine. Sometimes the slippage has been irritating, but more bothersome than resulting in any blisters, etc.
Happy shopping!