I haven't watched the HBO Max version yet, just seen some comparison vids and shots, but the DVD conversion handled the special effects shots very poorly. The original show was broadcast in SD 4:3 which is what the effects were rendered at. The DVD conversion went to 16:9 widescreen, since that's what the film was shot at, but then decided to get 16:9 effects shots by zooming in and cropping the already-low-SD-resolution renders. So it's now basically half resolution, and then run that through an interlaced DVD and put it on a big HDTV, and it looks awful. The effects shots also include a lot of conversations and other shots with people, since they used quite a few virtual sets.

From the comparison shots I've seen of the new version, they kept everything 4:3, and instead of cropping the effects shots, did a pretty decent job upscaling them instead. So it's not HD quality like if they were rendered in HD, but at least it's not sub-broadcast-quality anymore.