Just in case you want to compare with R-12, I just checked my vent temperatures in this hot humid Florida summer with completely original (refurbed) equipment, and I recorded 58 degrees with an ambient temperature of 92+, and 45 degrees with an ambient temperature of 85 degrees.
Picture was taken on 08/13:
I also heard about good temperatures from RedTek. Has somebody recorded vent temperatures recently that they could share?