Lots of Kerdi shower pans are flood tested, Jared. There are even lots of questions in threads here about the seams darkening when such testing is conducted.
Thus far we know of only one that actually failed, and, as is so often the case, we never really found out what was the cause of the failure. But it looked to me like the membrane had not been properly attached to the drain flange.
Also lots of threads on here with discussion of the infamous Kerdi beverage coolers, some of which have held water in a cardboard box for years. Re-use'em alla time when we have a function at the CTEF.
Only drawback I'm aware of is the required 24-hour wait time from installation to flood test.
I'd caution you about your enthusiasm about saving a lotta time over doing mud showers. If you're an accomplished mud man, you're not gonna see a great time savings in switching to Kerdi showers.
If you just Kerdi over prepared sheetrock boxes, you can save some time. Not a great deal, but some. If you hafta fix the framing to suit your requirements, re-sheetrock and install Kerdi, you're not gonna see a great gain.
Those of us who are only occasional mud men (or usta be) might find the two methods a wash as far as labor time is concerned. The Kerdi is easier work, though.
But at least one mud man known to me would lose a good bit of time doing Kerdi showers. At least for the first few dozen, I'd guess.
But for me, the big reason to change would be to have the bonded waterproof membrane on the entire interior of the shower immediately behind the tile surface, floor and all. Just makes good sense to some of us.
Others, not so much.
My opinion; worth price charged.
