I have both Crocs and Birks (pair of sandals & pair of clogs). I could not wear either all day in the parks. What worked best for me was to wear my good supportive walking shoes (New Balance) for touring the parks, then switch to the Crocs & Birks alternately in the evenings to give my feet a break (I have discovered with my issues with plantar fasciitis that switching shoes is better than wearing the same ones constantly). I did wear my Crocs the afternoon we spent at AK for their waterproof quality when riding Kali River Rapids, but I don't think they would have lasted all day on my feet (tend to rub blisters on the sole of one foot if I wear them for an entire day). The Birks wouldn't be cushy enough for all the standing for my heels to last an entire day touring, although I wear them for entire days when not on vacation (but then I can sit more frequently when I need to). The change-up of shoes was key for foot comfort for me rather than picking one pair of shoes for an entire vacation. With either shoe, you do need to have time to break them in (especially the Birks....don't wear them an entire day to start off with....if you've never worn them, your feet will need time to get used to them just as the shoes will need time to break in as well). Just my 2 cents of what works for me, being a wearer of both Crocs & Birks.