As has been the case for almost 3 years, the JVC HR-DVS3U DV/S-VHS dual-deck VCR is the lowest-cost DV VCR. I have used one for 30 months and have had nothing but excellent performance. I also use a Sony GV-D1000 mini-VCR and the two will play each other's recordings, even those on LP, with no mismatches. Forget about any synchro-editing, for automated assemble-editing between the two, as this doesn't work. They both function over FireWire to and from a computer and work with a standalone DVD recorder by FireWire. The JVC doesn't show frame numbers on its front panel or on an analog output display, but it does record them and passes them through from other FireWire sources. It won't read or pass through all the features on Sony Data Codes.
If I had to choose just one of the two to buy again, I would get the JVC, based not just on the lower price, but on the usefulness of its S-VHS deck and the internal dubbing and digital conversions it provides. I have taken many old S-VHS recordings and re-recorded them internally on DV tapes and then transfered them by FireWire to DVDs on my Toshiba HDD/DVD recorder. It does provide an S-VHS to DV pass-through function and also will take an S-Video input from a Hi-8 recorder and output it digitally over FireWire, with no re-recording required. However, unless the analog-to-digital conversion has been re-recorded on a DV tape, it won't carry the timecode that the DVD recorder requires to record it on its HDD or to a DVD.