Create a control for the experiment.
Did you try just one tape to make this conclusion, or did you run through several different types of tapes? (SP + SLP, homemade vs retail, etc).

I know CapDVHS can be problematic.

I tried several different tapes, both EP and SP. Unfortunately I don't have any commercial tapes on hand to try out, but I'll be visiting my parents this weekend and they have a huge pile that they don't really watch anymore, I'll grab a couple.

My first test tape was one that I was able to successfully capture using pass-through on an HM-DH30000U previously (don't have that VCR any more).

From the few seconds of video I AM able to capture, though, I like the 40000U's picture quality better than the 30000U.

Has anyone ever used DVHSTool? I tried downloading it (all versions that are posted) but the download always hangs up after about 500K on each of the files.

I haven't done any serious testing with CapDVHS. I was using VLC to stream/decode the output from the deck (goto File | Open Device...). I had no problems from analog sources from my brief testing. My machine seems to choke with 1080i DVHS tapes though with choppy audio. It might be VLC though since the deck's built in decoder has no problems playing back the audio.

No, and it's not just you -- it's been that way for years. The program look to be hosted on a person's computer, and some sort of firewall kicks in after 300-500kb has transferred. The "site" is using a dynamic DNS, which almost always means somebody is attempting to run a website from a home computer (HORRIBLE IDEA!!) instead of using a hosted solution.

I may try to contact him (via information gleamed from whois records), and see if I can get it, in order to have the file hosted here.