Conversion times depend mostly on the speed of your computer, though you can vary how the converter works slightly, to speed things up. In AVStoDVD, once you import your videos, click on the encoder settings (reel icon) like in this 1st picture.
Then, click on the Video tab and unclick the Auto Video Setup box, then set the encoder to HCenc OPV 1 pass. You can also go into the Advanced settings for HC and go to Normal or Fast settings to speed things up a bit more compared to the Best quality setting. All of this reduces the quality slightly, but speeds up the encoding times.
Once you remove the automatic control over the encoder, this means you have to make sure all the settings for your dvd are correct. Wide screen would be 16:9...full screen would be 4:3. If you are in the US, use 720 x 480 resolution, if you are in PAL standards country, use 720 x 576.