"White" LEDs from even the best suppliers can easily have a 10:1 variation in brightness coming off the same assembly line. So while a 1W LED might be vaguely equal to a 10W filament bulb...that 10:1 variation is still a huge one. In order to get LED specs that mean anything, you have to be ordering LEDs that have been sorted into matching "bins" and the vendor pays extra to buy them that way. With unknown chain of supply and unknown vendors...roll the dice.
"I see no value at all in LED replacement bulbs." Look again.
Prime LEDs are rated at a specific brightness, heat, and other characteristics. The industry standard is to rate the brightness (which is tied to power consumption
and proper heat sinking) by operating the LED so that it has 70% of the initial brightness after 50,000 hours of use, and it will not fail until some 100,000 hours of use.
If you take 50,000 hours as the standard for replacement...that's 4,166 twelve-hour nights of operation. More than eleven years of regular nightly use. You won't get that from any kind of filament bulb at any price
. There are special "instrumentation" bulbs with dual filaments that might come close--but they are also intentionally dim to last longer.
LEDs are like race
horses. If you just go down to the track and put your money
on the nag with a nice name? The bookies call you a sucker. Picking a winner in the LED business these days pretty much means you need to buy from a prime distributor of a prime manufacturer--and that ain't cheap
There might be something to be said in paying more up front, and getting a reasonable chance of not having to climb the mast
on a rough night for the next ten or twenty years to change that pesky bulb. Might.
I'm not sure "mass market" bulbs in a niche like marine lighting
are ever going to be reliable prime quality.