Let me preface this by saying I too wanted to simply digitize old camcorder VHS tapes into files so I could burn to DVD.
I ended up picking up a Pinnacle(made by elgato - Pinnacle just puts their name on it) HD stick for Mac w/ EyeTV lite. It sucked. First of all, the information on the packaging makes it seem like it will easily do this task. What I found is that without paying an additional $50 for the full version of EyeTv, you can't even pull the digitized files off your Mac, and I couldn't get any program to convert them. The HD stick with EyeTv Lite is literally ONLY to watch recorded programs or live TV on your Mac - that's it.
I took it back and got Elgato EyeTv Hybrid. It sucked too. It will only convert to mpeg-1 or mpeg-2 in real time - which if you'd like to edit your files, renders it useless straight off the bat in iMovie, because mp1 and mp2 mux audio and video together, which is a no no for iMovie. I also found that the initial video quality of the digital conversion was quite poor. Much worse than the original analog VHS source tape. Then, after using EyeTv to export the mp1/mp2 files into .mov or .mp4 files that I could use for iPod/iMovie/iDVD, etc, the video quality became abhorrent. iPod was the only medium that the quality video could be tolerated on. It was extremely grainy, and I had about 1/2 inch of the top of the video on the bottom of the video, much like you'd see if a TV's vertical hold is set incorrectly.
Fact is, if you are really looking to just digitize old VHS tapes or other older media, stay away from EyeTv Hybrid or Pinnacle HD Stick for Mac. You just have to jump thru too many hoops to get a useful end result, and that end result is certainly far too poor quality to justify jumping thru said hoops.
Get something that converts directly into .mp4, .avi, etc, etc - otherwise you'll get something that looks akin to a copy of a copy of a copy of a VHS tape.
EyeTv 250 seems to be the solution, but it's extremely pricey. I'm quite wary of any Elgato product now. Oddly, I had much more luck with Windows and Adaptec's Vide-OH! USB box and software in capturing quality video. Unfortunately, .avi was the only option to capture as, and it used some oddball codec that almost nothing recognizes. To this day, I can't convert these .avi's successfully with iSquint or any other program, and the only thing that has ever played them is a PC with Vide-OH! installed on it. I ended up using my pc laptop/Windows Movie Maker to capture video as .wmv's, and then toss them into iSquint for .mp4 conversion...