First the good stuff, though: It has yet to get squirted out of the pocket; the clip works well. It has yet to show signs of trying to chew its way out of my pocket, despite the aggressive "strike bezel". I assume that will be the eventual failure mode of the jeans, but it remains to be seen if it can chew out of a cheap pair of Lees faster than my IWB holster can tear a belt loop loose from its moorings (which is how I usually know it's time to bulk order another three pairs of jeans from Amazon.)
Like all SureFire lights, nothing in your day-to-day activities is likely to hurt the thing, unless your day-to-day activities involve getting run over by construction equipment or falling into the calderas of active volcanoes.
The biggest...only, really...gripe that I have is the switchology.
See, in addition to the sweet 500-lumen high power setting, there's a 5-lumen "running light" setting. I like a dimmer light for looking for dropped items under furniture or walking from the house to the garage. The high-beam setting is harder on batteries and frankly overkill for most everyday flashlight chores.
The problem is how the low-beam setting is activated. Here's SureFire's description from their website:
"[T]he E2DL Ultra is activated with a pushbutton tailcap click switch that also selects output levels: press or click once for a high-intensity 500-lumen white-light beam—ten times the light needed to overwhelm the night-adapted vision of an aggressor. Return to off and press or click again within two seconds for a 5-lumen ultra-long runtime low beam that's suitable for navigating at night or performing close-up tasks for hours."This has two potential downsides:
The first would be if you needed to pull the flashlight out in a hurry and light up a bad guy or potential bad guy. If you fumble and double-pump the button with your thumb, you've got a fistful of flashlight putting out the approximate lumens of a half-dead firefly.
The other would be if you were using the technique Chuck Haggard was demonstrating at the class I took at Paul-E-Palooza: You're searching for a possible threat with the light held up in the "Modified FBI" position. You spot a threat, go dark with the light, sidestep, and re-illuminate with the light held in a "neck index" for shooting. Only if you do that with the E2D Ultra, you'll barely have enough lumens to see your front sight.
This latter is a technique-dependent gripe, however. Mentioning it to LAPD veteran Mike Grasso, he brought up the countering school of thought: Namely, that when you turn off the light to move, the bad guy can move, too, so once the light goes on, it should stay on, and stay on the bad guy.
So how big of a downside the tailcap switch is is going to be up to the individual user and their brand of gun-fu to determine. I was firmly in the "Once the light goes on, it stays on" camp before I took the class with Chuck, and now I'm torn. I can see the upsides and downsides of both ideas...