Hey Raptor.

I use both the jetscream and the starflash and love them for my own reasons. Heres what I can base off of my own experiences after using a lot of the others as well.

Jetscream-(PROS) very,very loud with very little effort. When you put force behind it it will actually make your ears ring because its so loud but even a small effort will produce a very clear sharp signal. The holes are large and will not easily clog in a dusty enviroment(or in extream cold when ice can block the holes).flushing it with water will clean it right out. It is the toughest model I have yet used and can withstand abuse even when it is -50 deg cel outside.(my fox 40 shattered in the Alberta cold, and my slimline would constantly block with ice from my breath) It is flat and stores better than some of the bulgie types(in my kit anyway) and it is plactic compared to metal(the army still issues metal whistles which will freeze to your lips in winter if not careful)

CONS- For some crazy reason I could not figure out, all models came in black insted of a high vis color like yellow,orange or glow in the dark. this may have changed, I have had mine for a while now. They are some of the more expensive ones so buying in bulk may be a problem(7-9 bucks each) and they are a bit on the large side.(not ideal for a keychain)

STARFLASH-(PROS)This was the only model that stood up to Military use when used in extream cold weather. All other plastic models cracked on me.(my rescue flash came apart but the mirror part stayed intact,My Coghlans out right shattered) It will float quite well If you use it in a marine enviroment. Very lightweight compared to some other models out there.

CONS- Very easy to stratch. I cover mine with that foam stuff that comes in pocket flyfishing tackle and it works great. I wish they came with a protective cover of some sort though. I think it "aims" as well as the next but I wouldnt say it was any better or worst.

I cannot really say what is BEST in comparison to everything else on the market, That depends entirely on what you need/want the items for(for example, not everyone trains in the Arctic like I do) but I can honestly tell you that I have used these items in some of the worst possible places to find yourself in and have never been let down yet. I wont be replacing the starflash or jetscream in any of my kits in the near future because above all else they have served me flawlessly.

Of course, these are only my personal observations/experiences, hope I may have been a bit of help to you