I had an issue with the GAL in the Saturn 128k reboot card, it required a pullup resistor to get the DMA daisy chaining to work. Lattice GAL's worked fine though.
The ROM card works fine though. Both of the prototypes I assembled use an Atmel 28C256. I put an Atmel GAL in one and a Lattice GAL in the other and both works fine.
I was going to include the ability to write to the EEPROM but didnt work and only served to corrupt the ROM image when booting so I pulled that option from the production boards. Maybe I should have tried some other brands of EEPROM.