...does it work without Tivo service and what does it loose in functionality.
Without the TiVo service, the TiVo will act like a regular VCR, but with some pretty serious enhancements. You will be able to record whatever you want, but instead of specifying it by title (and having the TiVo record it no matter what day/time it shows up) you have to tell it to record by date/time. You can tell it to record every day, or every Tuesday (or whatever) at a given time.
The enhancements include things like...
You won't lose a recording because you ran to the end of your videotape. When the TiVo is full, it automatically deletes the oldest program (unless you have told it that that program is to be saved.)
You can watch a program previously recorded on the TiVo at the same time it is recording another program.
You can watch TV live on the TiVo, and pause the program for up to 30 minutes and then resume where you left off. (TiVo automatically recordes into a temporary file any live event your are currently viewing.
You won't lose a program because your videotape got all twisted and jammed during rewind.
You have instant random access (by program title!) to every single thing that is currently stored in the TiVo. You can watch as many different programs as you want simultaneously -- well, not simultaneously, but you can skip from one to another, and when you go back to a previous one it picks up right where you left off.
You can skip commercial breaks much more readily with the TiVo than with a videotape -- the FF speed is 60x normal, so you can zip through a 4 minute commercial break in 4 seconds. TiVo automatically compensates for the "overshoot" when you release the FF button.
You don't have to label, sort, and store videotapes, or try to remember which videotape you over-wrote to record the Canadian Grand Prix Formula One race. Even without the TiVo service, Tivo labels the programs by program name. Or does it? Now that I think about it, it may be applying program titles from the TiVo database, not from the signal source. Someone help me out here...
I have heard of TiVos hacked with as much as 120GB of hard drive -- over 100 hours of capacity. That would make a stack of videotapes over three feet tall even if you recorded the videotapes at lowest quality. And imagine trying to find the program you want to watch, stored somewhere in the middle of one of seventeen videotapes, each tape sith six hours or programming on it, and the only way you can check is to go through each tape serially. Why, that would be like trying to find a particular song in a stack of 150 CDs, instead of just pushing a button or two on your empeg...
Other than the archiving and picture quality issues pointed out above by Dan Zimmerman, the TiVo has *every* advantage over a VCR. And (this is just my somewhat naive opinion) there is very little on television that is worthy of extraordinary picture quality.
Hmmm... I better be careful, or people will start to think that I like my TiVo.
ps: I use the term TiVo generically. I am sure the RePlay hard disk system has every advantage that the TiVo does.
tanstaafl.
"There Ain't No Such Thing As A Free Lunch"