Regarding emitter. No, P4 vs Q5 etc. has nothing to do with run time or brightness. But it has everything to do with efficiency.
The Cree XR-E can take 3 watt - the Q5 being brighter than P4.
But which one to have the longest run time and brightness also to do with the driver - how efficient is it? An how much is it supplying to the LED? One light can choose to drive a Q5 with 1 w for long run time while another pumps 3 full w into a P4 - the P4 then being the brightest by far.
The one that got me really hooked on LED flashlights is the MTE C3-1 - sku.16543 from DX. I'm very excited by such a cheap flashlight. A small but powerful performer. Where I live it costs the same as a mini mag (they're expensive in Europe) but outperformes it by by in just about any way. But to run on full brightness you should use NiMH or Lithium if you fancy those (I fancy Eneloops).
An I really like the fact that it's stainless steel. Feels like solid tool built to last.
It is a budget light and as such there's small but neglible quirks. The head assembly probably needs to be tigthned when you get it. The end has two o-rings and the none nearest the switch interferres with the thread. Just remove it, one o-ring is more than enough. Other than that I'm very pleased with it.
I also have a SmallSun - sku.16606. But that's a bit special - not really a general purpose flashlight as those with reflector. Great throw but almost no spill. Don't really recommend it to a newbie since you need to be aware of a few things cause it's direct drive. I modded mine with a proper driver and multiple modes :rock:
Also have two Fenix'es, LD20 and PD20, waiting in the post office but because of opening hours I can't get them before saturday. So can't tell anything about them. But guess they're not fitting the category Budget Lights. Yes know they're identical except power source