Everyone has different thresholds for quality. Given that you are using a very good camera, it would be a shame to give up too much quality by over-compressing the video. Speaking strictly for my own tastes, I would not try to put much more than 75-80 minutes on a DVD when the source was good quality DV from a first-rate camera. Once you start getting into the 90-100 minute range, you are going to start noticing things during dissolves and fast action.

Of course if all you have is talking-head video, then you can probably put two hours on a DVD and not notice much degradation.

I have to disagree with johnmeyer........If the quality of the video is excellent, which of course depends on the lighting availble and the camera and the camera operator, you can put more than 2 hours on the DVD. If however you are shooting a candlelight wedding than no, you should not go over 80 - 90 minutes.

The quality of what is acceptable depends a whole lot on what you are trained to see. Here's an example of what I mean:

There was an interesting post about a month ago in the AVS forum from someone who had purchased a DLP projector. One of the problems these have is fringing during movement because the three primary colors are created by projecting though a rotating color wheel. Thus each primary color is offset in time from the other two pirmary colors. This can cause color fringes at the edges of the moving object. The guy who made the post knew about the fringing, but loved his projector initially.

Then, one day, he saw it. It had been there all along, but he just didn't know what to look for. Once he saw it, he couldn't stand it.

There is probably a moral to this story, but I won't attempt to describe it, other than to note that the only thing that matters is if you (or your client) is satisfied.

DVDA or Vegas should be about the same for rendering time. I don't think it would be worth rendering to AVI and letting DVDA re render. Time depends on how much effects, color correction etc. you have. 14 hours seems very long. I just rendered 1 hour video to MPEG 2 in Vegas and it took 1.5 hours. (almost stright AVI). You might get and hour and 45 minutes on a DVD if you don't have much else on it. If not you could play with lower bitrate and check quality.