I do not think many PC's have a scart line-in. Most current Multimedia PC's do have a composite video in but this is inferior to a direct RGB copy from the Humax to a DVD recorder using scart. With the Humax, the DVD recorder will need connecting to the TV scart, not the video one which doesn't have an RGB out.
I had previously made transfers of old tapes to DVD initially using a Pinacle Movie box, and later with a new PC it's video line in. Neither of these PC DVD transfers come close to that obtained using a direct scart connection from the VHS recorder to my Pioneer DVD recorder. Scrollling text on the PC transfers was unacceptable unless used at the best bitrate setting, 1 hour per DVD, but I wanted at least two hours. Even a lower bitrate transfer to the Pioneer was much smoother, even its 2 hour 20 minute per DVD setting.
I am certain that there must be high end PC video trasnsfer equipment that is used by studios to create commercial releases that works well, but dread to think what it would cost!
If one doesn't have a dedicated DVD recorder and has to use a PC, it can be done with a scart out to RCA connectors lead (normally Red/White/Yellow.)
Other things to consider is the time taken create the DVD on the PC. The video transfer has to be done in real time, then the DVD has to be 'authored' with a suitable package (eg Nero, Pinacle etc.) then processed to encode the data to your settings, and that can take the PC much longer than the initial transfer of the original real time recording; perhaps even 4 or 5 hours depending on the power of the PC.
Using a dedicated DVD recorder means that once the recording has been copied across, a menu can be added if the DVD recorder allows this, the content can be edited if the recorder supports that (cutting out ads etc.) and the finalising of the DVD takes a mere minute or two. A DVD recorder with a hard drive is even more versatile.
Another aspect to consider with DVD authoring on a PC is the amount of disc space it requires; it would restrict the PC's use for other things as it doesn't really like anything else happening on it while the DVD data is being processed; so ideally you'd need a second PC dedicated for video work!
If all you want to do is transfer a few recordings from your Humax to DVD, then yes, you can do it on a PC, but for regular use it is an absolute pain and a dedicated recorder is probably the far the better option.
Reference to the 9200T's USB transfer is not really relevant here as the 8000T doesn't have that facility. I haven't tried it from the 9200T's USB yet so do not know if the PC programs would need to reencode the streams or use them directly. Some PC programs re-encode transferred video as a matter of course, but not all do, so results on the PC may well depend on the software package used to author the DVD. However, I am more than happy with the RGB copies from either Humax to the DVD recorder.