For land I use the 14-150 anyway much more versatile for travel. I will probably add another used 12-50 later this year for specialty use (digiscoping) if I want one, as I am sure I will be able to find them for around 200 or so.
I have been curious about the wide wet lens also, but no one here seems to have tested it.
Also, you still have to factor the cost of the diopter when comparing equivalency of the lens set-ups. I guess the diff comes to about $150. Its great that you own them because you can use your diopters to get into ultra-macro range with the 12-50, or ultra-ultra macro range with the 60.
Just a story about the 12-50. I was on a dive late last nite. Shooting beautiful flamingo tongues in macro mode. A hawksbill turtle swam into my lights. I made an instant switch to zoom mode without having to take my eyes off the turtle. Would have lost sight of it for sure if I had had to unscrew a diopter and put it away. In about three seconds I was zoomed to 12mm wide and getting great shots of a turtle at night, something I never had in my portfolio. This is a good example of the combo giving me shots that are not otherwise possible. My buddies shooting macro with diopters never had a chance. I have several other stories like this, and have only owned this lens set up for 2 months.
I am very glad I did not save the $150.00.