We went on our Mendenhall Glacier Adventure Tour on August 27 with tour guides Matt and Ryan, and it was awesome! Matt and Ryan provided lots of super interesting info on the landscape and a plethora of equally dad-ish jokes (which I loved).
The only downsides were out of their control: mainly the weather, no ice caves, and sub-par canoe mates. The weather was cold and misty/rainy for the entire duration and no safe ice caves were accessible for our tour. And then the family sitting in front of my fiancee and me in the canoe were a bit shoddy with their padding, consistently splashing us and hitting our paddles with theirs (because of bad timing, which Matt and Ryan valiantly tried to remedy with group counting multiple times).
Other than these circumstantial things, the tour and the guides were awesome! The view was incredible (even with the fog/mist), the sense of comradery was warming, and we felt safe the entire time (remember to align your crampons with the slope of the glacier!). It was a fair bit of exertion, but it felt good to work for the views! We did see one "ice cave," which was about 2' wide by 4' tall by 3' deep. It was a nice photo op, but it wasn't that immersive, blue experience you hear about.
Huge kudos to Matt and Ryan for their energy and dedication to our safety and enjoyment! Even with the cons, this tour was a huge highlight of our Alaskan cruise!