I don't usually like to get into these kind of debates since I started taking the live and let live zen approach to pinball, but I'll put the quality of my products up against anyone else who is selling NVRAM adapters. It's not really the type of product that even has the potential for that much variability in quality anyway, assuming that the manufacturer is using original RAMTRON parts. It's an extremely simple product. Infinitely less complicated than a modern automobile. I'm pretty sure we're all using basically the same pins, PCBs, RAM, and solder. I've never seen anyone who's actually a customer of mine complain about the quality of my parts in an open forum or elsewhere and I've got 100+ happy customers over the better part of a decade. Years longer than anyone else who currently sells these adapters. Additionally, there is no RAM adapter on the market today which works with every pinball machine. Gottlieb system 1, for example, is not supported by adapters from any manufacturer. The RAMTRON FM16W08 in use by everyone (as far as I know) making these has a conventional data bus with shared input and output. The 5101 RAM had separate buses for data input and output. The vast majority of pinball machine MPUs simply jumper these buses together, in effect creating a shared bus like a modern RAM would have. That's what makes it easy to drop a modern RAM into the circuit, replacing the original 5101(s). Computing systems which use the data input and output buses of the 5101 separately won't be compatible with "basic" RAM adapters on the market today which are dependant on these buses being tied together.
See the conversion I developed for the Stern MPU-200 MPU to replace two 5101 RAMs with 6116 for more information on this concept.
http://warpzonearcade.com/?p=392
As far the the WPC date/time issue goes, another option is to install an NVRAM adapter and jumper the RAM so it's connected directly to +5V (jumper W6) and continue to use a remote battery pack or memory capacitor to keep the date/time. That way you won't lose the adjustments, high score, etc... if the batteries go dead. You should just need to reset the date/time. Technically you could do that without jumpering the RAM to +5V, but the batteries or cap will be powering the RAM all the time and drain faster.
Lindsey
http://PinForge.com