I have Frogs on my Ti Guru; I have Shimano mtb shoes, that have a wide toe box. However, I do get some hot spots after 20 miles, and since I am taking these pedals on my tour across Portugal, I am looking into getting different shoes. The sole is just not stiff enough. I ride this bike on really hilly rides/long rides, so I have to do something. The Frogs are great and I love being able to walk around. I have Speedplay Xs on my other bike and I, too, need the full float. The Shimano road shoes work for me, but they are super stiff. I had to stop wearing Sidis because they are just too narrow for me, and I don't even have wide feet.
Was at the PI outlet yesterday and saw a pair of PI mtb shoes with a stiff sole that I will look into.