i have two of the I390's.. and they work great. i don't think the trigger speed on them is super fast, but if you set it up right the trigger speed is fast enough. the images i have gotten from them have been very clear with no problems.

Mottz..... you may be referring to the 35mm model? i have found that with most of the stealth models after you get them set up and put on the "test" mode. it takes a minute or so for that function to work. once it is working you can walk in front of it and the green light will come on.