pat here's the deal....this sounds stupid but do it, it works. I didn't do this at all for 3 years with my T60 (i was thinking what are these people telling me to do?) but after losing a week's worth of stuff on HDtivo because i forgot that HD uses up 8x the space as HD, I listened to them. Turn on your suggestions if you didn't already. What happens then is tivo will start to record stuff on its own. Suggestions are :
1. always at the bottom of the list when ordered by date
2. never interfere with any program that you intentionally have recorded
3. easily turned off 'live' simply by going to that channel and turning it (if you need the tuner for something else)
4. will give you an approximate amount of space left on your tivo. (explained next)
my rule of thumb is one page of suggestions (they are all SD as far as I can tell) is one HD program. This is far from perfect as some programs are 2 -3 hours and some are 1/2 hour. But you will make up your own system if you do this (and maybe even count the hours). So if you scroll down to the bottom of your now playing list and you see 2 full pages of programs, you can probably assume you have about 2 HD programs of space left.
There are things you need to figure out though - and you will see why this isn't a perfect way, but it's the best we have. For example, in addition to the stuff i just mentioned, suggestions will only record when suggestions are scheduled to record.
Get that? For example, if i only show space for 2 HD programs of an hour, and only see 1 page of suggestions, that doesn't mean i dont have enough space. It may mean that between the time i erased my last program, HD or not, no suggestions may have been scheduled to record (thus filling up again the suggestion list). I hope you see what i'm saying but even if not, once you turn them on it will become evident what i mean as you study their fall off pattern.
As far as stretching, as stated above, it really matters what tv you have. I have a hitachi CRT and the 16/9 stretch works great. It's on all the time except when i'm watching OTA SD.
Thats another thing. Shows like survivor and apprectice (reality stuff) are never in HD but directvs quality is so poor for locals, i record the network stuff OTA in SD and dont mind the bars a bit. But keep in mind, ANY OTA will take up more space than SD over satellite. I use 8/1 ratio to be conservative. There are real numbers out there if you search for them.
Also beware of burn in on your tv (depending on technology) and if that's a factor, you can't watch 100% stuff with bars on or you will fry your screen.
one final word about space. If you get tired of not enough space, you can add drives. you can do it yourself by using software off the internet and buy your own drive or, for example, spend 200 bucks at weakness.com and get double the space you have now with simple directions and never touch a computer. I just did this myself and it's very easy. I had upgraded the long way before but got lazy so just spent the money for a premade drive.
if i was unclear on anything, ask again and i'll try to help
just hooked up my 2nd hdtivo so am having a ball with all this network HD