I've used Teasers and Screamers both. The one from Utah (
http://wasatchwild.com/teaser.html) is adjustable every which way you can think of, howver, you must use it with either 4 AAs or a lantern battery; unless you have stock in a 9 volt battery company! This unit has a photo switch option that turns it on at sunset and off at sunrise, nice in high traffic areas. The adjustment pods allow you a wide range of sounds. But, they can also be a pain if they get nudged a bit things can really change. Also, the photo switch mandates that you mess with the set to determine if all is working...you have to turn the thing on manually to hear the sound or cover the photo eye for a while to see if it is working. This is a pain for me since I like to stay back as far as possible from the sets.
The other unit I used was from DSE in VA (
http://dse-outdoors.com/). This unit houses all batteries and uses AAs (the Teasers require that the AAs be taped onto the outside of the case and of course the lantern battery has to be seperate). The DSE model has only an on off switch and it sends out slightly different sounds at random intervals. No pods to fiddle with and I can hear if it is working on the walk to the set most often. DSE also has a new model out that is yet smaller and runs on AAAs. You can hear the sounds by logging into their web sight.
I caught cats and a Badger at the DSE locations but nothing with the Teasers. I'm not bad mouthing the Teaser, it just was that the dang 9V battery set up didn't last worth a hoot; MAYBE overnight in cold weather and I was always forced to fiddle at the set to see if it was working. Tom now has included a AA pack to over come the battery issue. Although these AAs are out side of the case.
One of my DSE units got damaged (rolling around in the truck or the like) and the on / off switch was stuck in the on position. I returned it to the company and they are fixing it or will replace it free of charge (that was a pleasant surprise). Also, the switch is right there in the front so you can set the unit back in it's hidy hole (no pods to mess up the settings) and when all is done at the set just push the button and you know now that things are kosher. The AAs lasted a good month in the DSE unit. I should mention if you wish to use the Photo switch feature of the Teaser you can not hide the unit from the sun.
In my opinion, the value of the Teaser comes in high theft areas; on at night when no one is wondering about off during the day. The DSEs worked well for me, were reliable, simple to use and the company stood behind them. I ordered more DSE units for this year.
I have no coons in may area and saw no evidence of Coyotes around the sets with the units. The manufacures and oothers recomend making secondary coyote sets back around 75 yards to pick up the shy yotes that come a calling.
