Good point about the return policy, I think I'll give it a try if I can find the budget.
Also thanks for the remarks about the 3AL being too big. I never thought about it that way; I switched from 4 to 3 because I thought it would make the lower register sound a little bit fuller and easier to play. Also, I used to play tuba until about 15 years ago, so I figured I could handle the bigger size.
About the Wedge fitting guide, one question is "2. How would you describe you and your level of playing experience?*"...
Until 17 years ago, I studied tuba at the Royal Conservatory in The Hague, but then I joined the Royal Marechaussee and did not play for a year or two. Then I joined their band, but on Euphonium. I then played 3 years with them, but between 2007 and 2015 haven't played. Since 2015 I play at least once a week at rehearsal (and most of the time, that's all I play). So concerning the technical aspects of playing, I think I am somewhere between beginner and Intermediate amateur, wouldn't you agree?