Anybody Ever Use Omnicel Batteries?

This battery chemistry is supposed to be for ultra long use/slow self discharge. Usually used in gas meters, monitoring devices, ocean buoys , remote telecommunications equipment. They are very high density batteries, but I wondered if the would be any good in flashlight?

http://www.ebay.com/itm/New-OmniCel-ER34615-3-6V-19Ah-Size-D-Lithium-Button-Top-Battery-/171224723338?pt=US_Single_Use_Batteries&hash=item27ddc9ef8a

I wonder if they’re analogous to heavy duty alkaline, which have great energy density but their voltage and capacity drop drastically if discharged over 0.5A.

From HKJ’s review of the Panasonic Pro Power AA: