Ignore the ink on the battery i marked it as a good battery.
Is the R5-A3 as big as you want to go?
The R5-A3 is 98mm long x 21mm wide which is about average for a torch that uses one 14500 battery.
18650 batteries have almost 4 times the energy capacity of 14500 batteries. And a compact 18650 torch is about 115 to 120 mm long and 24mm wide. They are not much bigger.
120mm should be ok if the gain in battery life and more lumens is much greater also should be fine… I’m off to bed goodnight all 
Where's the "hitting the head against the wall" smiley?
Rojos may just be The Most Patient Man In The World and I wouldn’t be surprised if he drinks Dos Equis too.
All I know is after this I feel like drinking a case myself. 
I like the pictures, good to see a nice pic of a light with some wear on it. Yeah if that light is using lithiums then the lenser is really going to be a bummer. Might as well have ordered a Sipik SK68.
Probably ought to show him some beam shots to make sure sees the different leds - an XML in 2100 tube size is pretty different from what he has - for close up work he’ll like it (especially with lots of modes like Erik does).
My guess is he just has crap batteries ..he says it's bright when first turned on and then goes into the dumper ..he bought it as a combo off ebay ...I love how people don't want to buy from chinese vendors like dino or dx kd or the like yet buy stuff off of ebay ..Probably from much less reputable vendors (In China)..
There isn't a thing wrong with your trustfire light ..
you just have crap batteries ..
Do you have a multimeter ? Are you charging them properly ? fully ?
Do some research (on blf) and buy some decent batteries
I personally think you will like the led lenser . The build appears to be fairly well put together.Lots of people like them ....until you know better ,then you'll probably wish you spent your dime somewhere else ..We all do it and we all have a set of trash batteries or a dumb charger from when we thought we were being extra smart to catch a deal .. Best lights to buy on Blf are the ones the whole forum is falling all over themselves to get.Spend some time just watching and reading and it will be obvious what to buy .
You may be expecting too much out of the trustfire or a 14500 battery ..In which case the led lensers output will disappoint you ...and like someone suggested an 18650 light might be more appropriate for the kind of output you're looking for.
Welcome to BLF :P
Pictures of the charger for my old torch as requested …
Charger looks pretty slow (good for battery) - are you charging one battery at a time with it? Some like that need two depleted batteries in it to charge properly. How long does it take to fully charge (4v+) your 14500?
Boaz’s comments about the battery and using a meter to do some readings with it sound very valid.
If you can, what is the voltage of your suspect battery now? Is it fully depleted, or charged?
Takes about under 2 hours to charge two batteries, haven’t got anything to test the power in the batteries… Although i bought these a few days ago http://dx.com/p/trustfire-protected-14500-3-7v-900mah-rechargeable-lithium-batteries-2-pack-26124?item=6
Would these batteries do for this torch “EagleTac D25C Clicky” http://www.ledfiretorches.co.uk/eagletac-d25c-mini-1618.html
Maybe, I would recommend getting some decent brand name batteries and an Intellicharge I4.
One thing you shouldn't skimp on is decent batteries and a good charger.
Use CPF8 for a 8% discount from LEDFireTorches.
Well Scaru…………………Looks like you were right!!!
Seems pricey for just a charger ?
http://www.ledfiretorches.co.uk/sysmax-intellicharge-i4-quad-bay-charger-v2.html
EDIT: Although does look a good one…
You get what you pay for. THIS is excellent advice from someone who knows his stuff.
A safe charger is not going to get much cheaper. In fact this is a really cheap charger compared to other ones.
Are these batteries better then to go with that i4 charger and torch EagleTac D25C ?
http://www.ledfiretorches.co.uk/cytac-rcr123-3-0v-batteries-with-pcb-528.html
Yes, those batteries are better.