DV-AVI is standard definition and very lightly compressed. If you import AV-DVI into a standard definition project and export the finished project to standard definition, it's very unlikely that you will be able to see any loss of quality. If you import AV-DVI into a high definition (e.g. AVCHD) project the quality will depend on whether or you scale up the AV-DVI to match the larger frame size. If you don't scale up the DV-AVI, the quality will pretty much match the standard definition DV-AVI source, but, the standard definition video will not fill the high definition frame. If you do scale up the DV-AVI, the quality will degrade. in general, the scaled video will be less sharp, may have color fringing, may have jaggy edges, and, of course, you will be magnifying the noise as well. That's not to say it won't be acceptable. But, that determination will be yours to make.
Here is an
article about up scaling that you may find useful. It addresses up scaling in Premiere Pro, After Effects, Photoshop and discusses various plugins that could be used.