Soldato
Unless you need it for gas or explosive vapour use you won't find many with pellets.
As for spec most are fairly acurate as they get independently tested by variuous users over on the Candle power forums.
That said some are more acurate than others and as usual you get what you pay for.
Also beam patern afects how you percieve output, I have two lights with 220lumen output 1 is narrow throwy beam the other slighty more floody at close range floody looks brighter and lomg range throwy or narrow beam look brighter.
How can a tiny little light be better than a big ass strong powerfull torch like for example a 6d maglite.
If in doubt as to the output some are capable of check out this site
http://fonarevka.ru/
have a look at Dam view 1 and compare a Maglight 6d cell (amazon price to £26.44 excluding batteries) to a Eagletac P100C2 only 220lumen and same size as a mini mag (£34.95 inc batts from flasaholics) and just for fun see the Fenix tk40(same as tk30) 630 lumen or on the mad insane side see the Polaron PH50 5000ish lumens (a bit of a cheat as its a HID light)
These lights are a lot better than people think
Even the cheapy lights like the Ultrafire wf-1000l perform well if lacking a little in build quality.
You dont have to spend lots or buy the biggest to get decent power my Fenix pd30 fits in my pocket fine and beats a big ass maglite
Any torch claiming to be IPX7 waterproof should carry Hydrogen pellets, especially if they do have an air tight battery chamber.
In regards to testing, there has to be a standard which is what ANSI provides. For example, how do you test run time? Some manufacturers will claim long run times but the light source is near useless for majority of it.
We have a plant in the US which is predominately for R&D and we get to test other products too.