Sci Fii, sorry for my late reply...
... How's the throw on the 4 and 6 cell lights? Can either do 200 meters with reasonable light?
the 6-cell Magnum Star Xenon beam can reach >100 meters in these host, but I'm not sure about 200 meters tho... as these are using a relatively shallow reflector. The Dolphin can throw better than the Waterproof model. If you are looking for better throw, maybe the bigger D-cell Dolphin is the model to get.
...Why don't you use the 14500's in the ACE model. Would there be a problem doing so? ... Is there any reason besides heat I couldn't do this with mine?
I left the the ACE model in stock form due to the quality of the contact point, not heat. It also serves as a comparison checkpoint for me.
...One other thing. What are the three round Eveready's called? Are they also Dolphins?
The three round Eveready are not Dolphin, they are called Eveready Waterproof light, but their waterproof are tested only to 3ft for 1 hour as printed on the card. It floats too.
I like these Eveready Waterproof light as they have a bigger base and can be easily "bored" to accommodate 18mm LiIon cells for longer runtime and it's smaller than any D-cell lights.