In my opinion, the Plot Watcher time-lapse cameras are good for one thing in particular--monitoring a large area (such as a big food plot or field) to help in identifying deer movement patterns across the area during daylight. With a regular trail-camera, a deer has to be close enough to trigger the motion sensor of the camera. That can be difficult over a wide area. The time-lapse systems have no motion trigger. They just take pictures at set time intervals.
However, they do have their downsides:
1) They only take daytime pictures.
2) Low image resolution. Deer in the distance will not be identifiable as unique deer (you won't be able to see rack details).
3) Very short battery life (no more than a week).
4) To get the best information, pictures will need to be taken frequently, hence you will be faced with assessing thousands upon thousands of digital images. One user I talked to said he collect 14,000 images in a week. That's a lot of pictures to go through.