Because we boondock often and in colder climates, one of the first upgrades was to add a second propane tank to our 177, which was purchased in January 2011.  I never considered adding a switchover regulator because it takes maybe 20 seconds to unscrew and re-attach the coupler to the fresh tank, so it came down to a matter of why spend the money when I am not saving any time in doing this 'upgrade?'

Time wise I don't think you save much if any time for when your tank runs out, you still have to unhook it to refill.  I guess the only advantage would be when you run out, which in my case us usually about 3 am, you save the hassle of going out in the middle of the night to switch things out.