John, some info to help your decision.....
I have recently considered buying one of these fiberglass tanks myself because my original aluminum tank is 13 years old and legally cannot be refilled.
I say "legally" because if the dealer filling the tank doesn't check the date and just fills it, you can get away with using a tank that is more than 12 years old that has not been re-certified.
So I was anticipating that sooner or later my refill dealer will check and refuse a refill. So I did some research.
According to federal regulations, a METAL propane tank (steel or aluminum) is originally certified for
12 years. After that, the tank must be re-certified and a new date stamped into the tank. Each certification extends the tank use for an
additional 5 years. I read somewhere (can't find the link) that a metal tank can be re-certified three times for a total of 15 years after the original 12 years.
See this link:
http://www.propane101.com/propanecylinders.htm#cylinderrecertification
Now the fiberglass tanks have a DIFFERENT life. Because they are not metal tanks, the initial certification period is not 12 years but only
5 years. After that they can be re-certified two more times for a total life of 15 years.
See this link from Lite Cylinders:
http://litecylinder.com/faq/
Now the certification can only be done by a qualified company. Finding one, getting the tank to them, and paying for the re-certification may be more expensive than just tossing the tank and buying a new one. Re-certification can be done with a hydro test or a visual inspection. A visual inspection should be fairly inexpensive, but you still need to find a company that will perform it. A refilling dealer
may not be qualified to perform re-certs, but some might be qualified. You need to ask.
Assuming that re-certification is not cost effective, then the life of the tanks will be the INITIAL certified time. That is 12 years for a metal tank and 5 years for a fiberglass tank.
Now you can do the math. Cost of the tank divided by either 12 or 5 gives you the cost per year. You decide how much the see-thru feature is worth to you and then you will know what to buy.
My solution? Well, since my refill dealer just refilled my tank, I am good until next Spring so my new tank purchase is not urgent. I did go to the Chinese Emporium, Wal-Mart, and for $5 I bought a dial-type 50# spring fish scale. Calibration tests showed that it was accurate to within 1/2 pound. Now I can weigh the tank on-board and determine the amount of propane remaining when I think I might be low. The tare weight of the tank is stamped into the tank on the protective ring.