Hi Davidra -
The specs on the bulbs sent to you are as follows
Carley 808 specs
9.6v 1.20a
MSCP of 23 = 239 b-Lumens/188 t-lumens @ spec. Around 250 t-lumens on 4x123.
The bulb doesn't like too much overdrive and there were a few reported flashings from those testing it on 4x123. I never had any flash, but the bulb capsule blackend too quick for my liking. If you look closely, you'll see it on the sample I sent.
Carley 809 specs
10.5v 1.20a
MSCP of 25 = 314 b-Lumens/204t-Lumens @ spec
On 4 fresh 123 batteries it starts at spec, but is underdriven for most of its runtime. The Carley 809 really perks up on 4.5x123 in a 4C though. Doubling to a 2x4.5x123 stack then fits in a 3D and I've used it as a LOLA to the HOLA 1185. In the double stack confuration, the 809 gives around 2 hours of light and really is impressive.
Carley 820 specs
10.0v 0.80a
MSCP of 17 = 213 b-lumens/139 t-lumens @ spec. Just under 200 lumens on 4x123. At 8 watts, there are no heat problems so one is not required to upgrade the lens/reflector.
In terms of comparing runtimes, you'll want to look at the amps each bulb draws...the lower the amperage, the longer the runtime.
Here is the estimated runtime on 123 batteries...
the GH24 @ 1.70a = 33 minutes
Carley 808 @ 1.20a = 53 minutes
Carley 809 @ 1.20a = 53 minutes
Carley 820 @ 0.80a = 90 minutes
Can't wait to hear the results of your testing!