How does (or should) the battery effect a decision on which handheld to buy?

So I'm looking through the various choices on 405nm handheld lasers to buy (this will be my first one) and there are a LOT of options.

They come in all shapes and sizes, and naturally many of them take different kinds of batteries:

AAA
CR2
CR18650
CR123A

Are the most common. But which to buy? For those of you with more experience, how does the type of battery a laser accepts affect your decision to buy?

What are the pros and cons? Many of the handhelds i'm looking at seem similar in features and host, but the battery types are different. It would be great to know how battery type should effect my purchasing decision!

CR18650
CR123A
the 123a dont last as long as the cr18650 but they are smaller so the lasers are generally smaller unless they use 2 of them
i would say the 18650 due to it has the most life.
it has about 2x of the 123s.
i would not use any laser that wont take recharge able batteries.

Thanks for the info, Kiyoukan. Are you taking into account that most devices that use CR123a use two of them?

So a single 18650 still beats two CR123a's?

the only reason they use 2 of them is to get that nice 7.2v that way you dont have to use a boost driver.
they are put in series so you get 2x power same life.