The Catalina is most definitely at least one aircraft that was attributed with take off at 90, cruise at 90, land at 90. I've heard this stated by some various old-timers (vets and aviation historians) throughout my life, and also it can be quite easily backed up through use of the internet now-of-days of course. These speeds are of course equating to KTS, not MPH, and they aren't exactly 'specific', but were a common reference to a combat-loaded Cat...I think you'd have to be in a bit of a dive to achieve 120 KTS (138 MPH!) in a Catalina.
As far as the Aerosoft Catalina goes, I find that with the engine management turned off (easily done - you can manage the engines just as correctly, if not better, with it turned off), it is just superb, and flies and sounds just how it should - gobs of lift, next to no speed, and surprisingly quiet engines at cruise. Growing up, I lived just about 3-4 miles from a locally operated Catalina, and was treated to the sight of it flying over every now and then. If it was ever high enough up, say 2-3,000 ft, it would simply spend forever in the air, as it slowly passed over, and if you didn't see it, you would never know it was over you.