Around 2009, I replaced all of our interior
overhead non-dimming 10W G4 incandescent bulbs with warm white (9-LED) bi-pin replacements and I swapped the exterior bridge G4 overheads to red (6-LED) replacements. All these were from Mastlight.com, at the time, and billed as more voltage tolerant for the marine (DC situation) environment
. (Mastllight has since gone south, and I think their website redirected to marinebeam, at least at one point.)
Last season, I began replacing all the remaining interior
incandescent 10W G4s -- on the dimming circuits -- with 12-LED (and a couple 10-LED) warm white G4s from marinebeam.com. Excellent, so far.
But during the process, I also replaced and/or moved some of the earlier LEDs... and discovered some significant evidence of heat damage on the backplane of several of those older ones. The backplane on the newer marinebeam products is significantly more intricate than on the earlier lights. (I suspect partly from evolution of design; i.e., not just comparing build quality.)
Also, about half the LEDs on several of the older 9- and 6-LED versions fail to light most of the time.
My LED project
this season is to replace all the earlier LEDs with new from marinebeam.
In the meantime, the 9-LED versions did give us plenty of light, at the right color "warm white" temperature... and made a significant difference in our energy budget
... so well worth the cost, at least for us.
From reading, it seems some folks have good luck with the $2 LEDs, and most don't. I suspect maybe some who "do" have good luck are giving early -- not time tested -- reports.... but that's just theory. I don't usually have time to do things twice. The heat issue speaks to me as well; a couple buck$ here or there isn't worth my worry about potential fire damage.