Yes you can just keep adding on to the disc until it's full(and playback anytime you want, you don't need to wait until the disc is full but if you delete a title other than the last title you won't gain back your full time). If you're going to play it on the recorder you don't even have to bother with finalizing the disc which would take a couple minutes. Panny users also like to use RAM discs which are harder to find B&M and less compatible with DVD players but they potentially last longer and have the advantage of chase play where you can begin watching a program while the end records. You can also play one title while another one is recording, you also gain back the full time when deleting any title, not just the last one like on a RW disc. On-line they're not much more than -RWs can be B&M.
On unfinalized RWs and RAMs you can either erase titles or just reformat the disc, either takes only ~10 seconds. Finalized RWs can only be reformatted.
PQ is kind of subjective but when I switched from VHS to DVD my "noted" original comparisons were(on a '05 Panasonic ES-30v DVDR):
LP-better than VHS SP, very good
EP6-as good as VHS SP, but for copying DVDs stick to LP, big drop in resolution form LP
EP8-like VHS SLP, maybe for unimportant timeshifting
My original impressions on 3575:
HQ1-Like Panny SP
SP2-Like Panny LP, fine
SPP2.5-Like Panny ep6 big drop
LP3-Like Panny FR7, more drop
EP4-Like Panny EP8, quite bad
SLP6-Like Panny FR12(just guessing not a valid Panny speed) Awful
Since my original Panny notes 3 1/2 years ago I've switched from LP to FR3 for things I care about due to macroblocking in the LP speed. I still occasionally use EP8 for talk shows when I don't care about the PQ and if I care a little I use EP6.
If you're used to VHS SLP I think you'll be fine with EP6 on a Panny and if you were a SP user like me you'd probably want to use FR3 or maybe LP if the subject matter doesn't have a lot of motion.
My notes for PQ were similar for other brands of DVDRs other than Panasonics, that is other brands I tested were similar to my Philips 3575 findings. I never tested a Pioneer made Pioneer or XS series Toshiba. I did test Sony, LG, Liteon, Centrios, Ilo and Cyberhome.
CYA part, these picture quality assessments are only mine and others may notice different things, I'm just sharing them with you since you asked