I preach the same thing - keep an R-12 system filled with R-12 at all costs, do NOT convert to R-134a or any other "refrigerant" (and I use the term loosely) that requires PAG/POE oils. People who whine about the "high cost" of R-12 are extremely short sighted, as a huge percentage of 134a conversions die within a few years, requiring exorbitant expenditures to repair. I'll not even get into the whole duct temp issue, where you need R-12 (or R-406a) to get decent temps at high ambients (basically anywhere in the south and west USA). OK, ok, end rant.
