Wow! 25 of these units. I own just sixteen functional Panasonic DVD recorders or combo recorders (plus a few parts machines) but mine are spread over the 2005, 2006, 2007 and 2008 model years.
I have the Service Manuals for several 2005, 2006 and 2007 Panasonic models but I never found a source for the 2008 Service Manuals. The main differences between the 2007 and 2008 EZ series models are the primary chips on the Digital PCB, a matter not addressed in any detail in Service Manuals since the remedy for a bad Digital PCB is replacement rather than repair.
I am fortunate to have one reasonably reliable 2008 DMR-EZ28V model, but my other four EZ series machines are the 2007 DMR-EZ17 models that have more than their share of design flaws and bugs. Firmware updates do not correct the problems and various workarounds are necessary to maintain functionality of the EZ series machines. There are extensive discussions of the EZ series problems and some workarounds at the AVS Forum.
The best Panasonics are from the 2005 and 2006 model years, Panasonic's "Golden Age."
I have extensive dubbing/copying experience (5,200 titles) with the 2005 DMR-ES30V model (two of these) and the 2006 DMR-ES35V model (five of these) combo recorders. These are outstanding dubbing workhorses as long as one uses the FUNCTIONS menu initiated dubbing/copying features such as Time Limited Dubbing/Copying with or without the Flexible Record Dubbing/Copying feature. When attempting to copy videotaped recordings with the built-in VHS section of an EZ series combo recorder one is limited to using the front panel control. The use of this control prevents the user from choosing/specifying various settings, with abrupt stopping and starting of recording and arbitrary creation of new titles that have overlapping program material. These are just some of the crude results that are the makings of dubbing/copying nightmares. I have described, in many posts at the AVS Forum, these and other drawbacks of using EZ series combo recorders for dubbing/copying. Here is the most recent of such posts:
My advice is to purchase one or more Magnavox H2160MW9 HDD/DVD recorders (once again offered at walmart.com), attach an external VCR to an input, copy the videotaped recordings to the hard drive, edit the video if you wish, then high-speed dub to DVD. I own two Magnavox HDD/DVD models (2080/2160) and two of the (similar) Philips HDD/DVD models (3575/3576). (A month ago I upgraded the Magnavox 2080 with a larger hard drive, a project that took but fifteen minutes.) These Philips/Magnavox HDD/DVD recorders are much more flexible and reliable than the EZ series Panasonics. There is extensive information and thousands of owner/user posts discussing these models at the AVS Forum, found here: