Pros
Set Top DVRs are great for controlling live TV and for setting shows to record days or weeks in advance, or to record entire seasons of a show. They are relatively easy to set up and the prices continue to drop.
Because you do not need to record to a tape, you don't have to keep a large number of bulky videotapes lying around to record with. In addition, you don't have to remember to put a tape into the machine every time you want to record something. Just remember to set the show to record and let the DVR do the rest of the work. You can even set a show to record every week and not have to touch it again, just watch it whenever you like.
Cons
One potential drawback for Set Top DVRs is the limited hard drive space. Eventually, if you're doing a lot of recording, your hard drive will fill up and you'll need to delete some shows. This may or may not be a problem depending on how often you watch the shows you record and the size of your hard drive. With DVRs, in order to save your programs, you must either keep them stored on the hard drive or record them to a VCR or DVD Recorder.
DVRs like TiVo and ReplayTV offer sophisticated Electronic Programming Guides that allow you to control how you watch TV in ways unheard of with a VCR. However, in addition to the cost of the DVR itself, you must pay a monthly fee to use their EPG. Cable and Satellite providers also charge a monthly fee, but do not require you to pay for the equipment. The equipment is leased and must be returned (in good working order) if service is cancelled.
DVRs from Sony, Panasonic and others do not offer as sophisticated an EPG, and are typically used in conjunction with a built-in DVD Recorder for transferring TV shows or home video to a DVD. These machines are more expensive than a TiVo or ReplayTV machine, but no monthly fee is required.
The End of the VCR?
The VHS VCR had a nice twenty year run as the king of the video recording world. Today, while not obsolete, the VCR is slowly being replaced by the new technologies of the 21st century. Digital Video Recorders are poised to explode in the years to come as prices drop and consumers embrace the new technology. Time-Shifting, while not new, is the future of television. It allows you to watch and record TV on your own schedule.