I have been using trail cams for 15+ years, starting out with the Camtraker @ $400.00. I still use this film camera near the house. When my film supply runs out it will be retired. Great camera. 4+ months on the batterys.
I have tried some other brands and I now use 4 digital cuddeback captures. I feel that these are the best for the money. Yes, I use flash cameras. I put them anywhere from 10-15 feet up and angle them down. Deer never seem to run from the flash or even look up at the camera. I have several sequences where a deer will come in on a scrape and I will get as many as 9 flash pics in 10-15 minutes. This position almost always gives a full view of the rack, no people seem to notice the camera and even if they did, I remove the 4 tree steps I used to put them up there. I get about 2 months on 4 D cell batterys
Cost is $200.00 list price. I have been buying them on E-Bay for around $160 -170.00 Keep the camera as simple as possible.
One thing I have found though, you will more than likely have to send it back to the manufaturer at least once in it's lifetime for repair. Do not waste your $$$ on cheap cameras.
I am a measurer for Boone & Crocket and Pope & Young so remember, if you take a record book class deer with the aid of one of the cameras that sends pics to your cell phone, it will not qualify for the record books. Again, keep it simple!