[Jayce]

There is a subject on these on the 'other forum' that mentions using 6 AA batteries as well. The guy rigged a four battery case (which has the 9 volt style connector) to a two battery case that actually fit into the 'A' version of these radios. Sadly, the only picture they have is of the finished product in the radio! No pictures of how they rigged things up between the two battery cases.
As far as performance goes, I've never noticed anything better with a 6 transistor model either. I've has several of the RCA models from the same time as these GE units and the RCA's tend to be junk when you find them. Either they used an odd battery voltage, or the RCA models used two D cells, which you always find swollen up and exploded in examples around here. The acid usually eats the board! Of the few I've found that were taken care of, the boards are usually split in the same spot due to RCA cramming them into the case. Oddly, I've yet to stumble on a GE that bad. I've seen some with broken cases that are still fully intact inside.