Can you preserve HD/Blu-ray's original quality at 4/8gb?

[broaddd]

I am thinking of encoding my HD in particular to my media centre in 720p format (as I'm intending to connect it to a 720p projector)...

...I've noticed other enthusiasts encoding in .264/mkv down to typical sizes of 4gb or 8gb (presumably so you have the option of backing up the encodes to DVD-R or DVD-DL), or bigger.

If anyone has general experience with the quality of encoding to say 4gb or 8gb, I'm really interested in comments on whether the original quality of the HD-DVD is well-preserved; or if it introduces noticeable compression differences.

Cheers!
B

[Baldrick]

Yep, it's well preserved. I would use 8GB as you might see some compression artifacts on a 2 hours movie in 720p compressed to 4GB. I use MeGUI(click on it for guides).