Because not everything gets exported to DVD
You dont export to Encore unless you are making a DVD from your PPRO Project
If I want to make a DVD, what are the inherent advantages and disadvantages of
a) exporting from premiere to some intermediate filetype, then importing into Encore
b) importing a sequence straight out of a premiere project into Encore
Exporting a MPEG2-DVD intermediate file means you can check it before you burn a DVD with it (and find there is an edit or encode problem).
It gives you a Master file should you need to take it somewhere else to burn it.
Handy and quick if you have a Stock Encore Project set up to just drop the MPEG into ( like I do)
otherwise... not much advantage or disadvantage IMHO
A nice advantage to Dynamic Link is that you can import your assets into Encore and manage the transcode settings there to maximize quality with the given disc space.
For example, if you have 2 hours of material for the DVD, along with menus and such, you can trial-and-error the transcode settings inside Encore to get everything to fit on the disc at the best possible quality.
You can of course acheive the same thing through the proper planning and bitrate calculating...but by using Dynamic Link, you save yourself from that task when you either don't have the time or the confidence to calculate your transcoded asset sizes.
Another nice thing is being able to make changes in Premiere Pro and have those changes updated in Encore. Again, with the proper planning, you can avoid having to go back to your Premiere Pro project in many instances, but it can be very handy to link in a couple of sequences, export a quick Flash DVD project for the client and be able to make any needed changes in Premiere Pro that are immediately imported to Encore.
There are also "Edit Original" functions in Encore, but I have found Dynamic Link to be more reliable.
As for whether it is faster or better quality to use AME over Encore for transcoding assets, I really haven't ever tested that. My guess is that results are probably pretty similar between the two.
I'm not aware of any bugs that exist with the Dynamic Link workflow at this time either, so again, probably going to be similar results between the two.
I vote for dynamic link. With CS5, it works well, and saves a lot of time and space. I would also definitely recommend making a disc image from Encore as soon as you have have a final final product, since the dynamic link chain can get hosed pretty easily by moved assets.
While I don't practice exactly what Bill is preachin' I will say I agree...making an image is a good plan. I personally maintain a DVD of all my projects, which is very easy to duplicate in Nero as needed, but a disc image is more versatile. Probably the best bet is to have both.
And yes, Dynamic Link doesn't like when assets are moved, so like all good things in video production world, pre-planning will save you plenty of heartache. If you DL (Dynamic Link) assets from 3 different hard drives and then move any of them somewhere else, it's potential going to break the Encore project.
Encore really is the weak link here. In Premiere Pro and After Effects, it's rather easy to reclaim asset links, and easy enough to package up projects when you're done (although upon my last check, there were issues with packaging the AE projects when DL is used in PPro...but that was CS4, haven't bothered with it since I came on to CS5).
This goes under "Feature Request" but I think it would be nice to have a central app that condenses a project once you are done...something that will collect all CS5 app files associated with a PPro, Encore or AE project and work very much like the existing project manager, but something centralized (like AME works).
I'm still getting used to CS5 DL after a brief experience with CS4 en route from CS3. I'm really liking DL. FYI, since no one mentioned it, the moved projects etc appear to be handled by "locate asset." That is, as long as they are somewhere, and not deleted.