It's always tough recommending torches as peoples expectations, experience and how they plan on using it makes a massive difference.
I let a friend borrow one of my SC52's a few weeks back, he'd only ever used cheap torches or maglites before, he was visibly stunned by the output from a torch so small.
Another mate who does a fair bit of trail running at night felt the tint on the same torch was terrible.
Funny thing is, this guy runs on extremely rocky paths at night with a H502, a torch that i personally find pretty much useless for walking with, never mind running.
For me personally i tend to prefer a torch that has more throw for night hiking, as i find i tend to like planning my footsteps a fair way in advance, i've also found that if you have a beam strong enough to enable you to see say 20 meters in front, it helps me judge obstacle heights as the shadow from said obstacle will get smaller as i approach it.
On the battery front.
One of my other hobbies is radio controlled cars, planes, copters, boats, as a result i've been using Lithium batteries in these craft a few times a week for what must be over 10 years now.
I've seen many many fires from lithium batteries, from crashes, bad charging, bad care and just plain bad cells.
One of the most violent battery incidents i've seen though was from a NiMH battery.
The guy was charging his cells inside his car on the passenger footwell, one of the cells literally exploded, the car was burnt to a crisp by the time the fire brigade arrived.
It was 100% user error, the guy had blocked off the cells vent, plus was charging incorrectly, it still goes to show though that ANY battery can be dangerous if mishandled.
Lithium batteries do get a bad rep as they're a little more sensitive to misuse, personally though i NEVER leave ANY battery unattended while charging and i always charge outside with a mindset that the cell will pop/fizz at any time.
It sounds extremely paranoid but in practice it really makes no difference if the batteries are charged in my office, kitchen, bedroom or outside, the setup is exactly the same and it takes no more time.
So setting up outside takes no longer but offers a lot more security "just in case"
With regard to batttery choices, although many people prefer AA or AAA powered torches because batteries are easier to find, i have to say that in my experience this is not the case.
Sure more stores sell AA or AAA batteries than 18650's but will you be near a store when you need one and more importantly will the store be open?
For me i tended to find that i'd just simply take along more batteries as finding a store 1/2 way up a mountain at midnight proved difficult.
If i take more batteries then i figured that's the convenience of AA's ruined so how about weight?
One of my Eagletec 3400mAh 18650 cells weighs 48 grams
One of my Sanyo Eneloop 1900mAh AA cells weighs 26 grams
Sounds a close race until you realise that the Eneloops are 1.2v and the 18650 is 3.6v (both nominal voltages).
3.4 amp x 3.6v = 12 watts
1.9 amp x 1.2v = 2 watts
So i would need to carry 6 Eneloops to provide the same power as 1 x 18650
6 x Eneloops = 156g or over 3 x 18650's