I just started using the SRT 3 this month. I fly a 747 and the uses here are the exterior pre-flight, checking cargo and cargo door security on the main deck, and at night when I need to go back on the upper deck to find something. In the cockpit there is plenty of lighting options, but it does get dim enough for cockpit use if ever needed. It is plenty bright using a single AA NIMH rechargeable battery. I may switch to using a single CR123 for the longer run time and brighter beam. The tail of a 747 is 69 feet high and ours are painted black, which seems to absorb light. But the SRT3 does an admirable job of illuminating it.
I leave mine set to the min level so that I don't blind myself or anyone else when I turn it on. While I primarily carry this in my flight bag (in a PVC tube) it does find it's way into my pocket at times. The ring has never moved as a result. But it is easy enough to turn the ring with the light off so that you can turn it on wherever you want.
I chose the SRT 3 over other models because...
1. battery flexibility
2. compact size
3. The infinite adjustability
4. Ability to tail-stand
5. The red LED is nice to have, but I rarely use it.
Downsides?? well if I had to pick one...I would pick the min level on the adjustable ring. To me it does not get dim enough. As one poster stated, if it would go all the way down to "0" it would be better. As it is, it supposedly goes down to .01 lms, which is useable, but I would like dimmer.
I have no need for the flashing modes and would prefer a light without them. However I was flying with someone recently and was showing him the alternating-flashing red and blue mode. We were debating taxiing in with that mode in the windshield to see if anyone would say something like "when did the police get a 747?"
Overall...I am happy with my choice and plan to keep it in my flight bag.