As it turned out, my tanks were solid as a rock...just rusty as heck on the outside...which leaves one in doubt no matter what the repair if some experts claim many rust from the inside out.
Plus they had a layer of crud in them that was only coming out with a scrubbing...no amount of motion and polishing was getting this out.
Plus I more than doubled the amount of storage space in my engine room. Utilizing space on a liveaboard that was being wasted by storing old fuel didn't make sense to me.
All in all...I would do it again for the reasons stated even if I had a guarantee the tanks would have lasted another decade. With no gurantees, cruising away from home 4-6 months of the year, replacement on my terms seemed a no brainer.
But as in all things boating...if I couldn't do it myself, I couldn't afford large boating at all.
Plus, not too many options I think that are all the easy, practical, cost effective, really effective, and have as many plusses in other columns that I like.