I've listened to the Art Audio and Audion PX25 amps in my home. Where are you located? If you are buying in the US, Audion's US distributor here in Los Angeles has an excellent local technician and he stands solidly behind everything he sells. You should not worry about Audion reliability. I have 6 Audion products in my various systems and have had no problems with them.
Of the two amps, the Art Audio is the more romantic sounding. It is warm and euphonic, certainly very good. The Audion is the more accurate however. It is fast and defined, highly resolving, especially the hand-wired Mark II version. I've heard it with KR PX25 tubes and it was sensational if you prefer an objective presentation of fidelity. The bass from this amp is about the tightest I've heard from a triode tube amp and in fact it didn't sound triodey at all -- very much better on the bottom than any 300B. The PX25 is a slightly lean sounding tube, not lush like the 300B on top. But mids are breathtakingly clear, an Audion strength. I'd go with the Audion.
Phil
Of the two amps, the Art Audio is the more romantic sounding. It is warm and euphonic, certainly very good. The Audion is the more accurate however. It is fast and defined, highly resolving, especially the hand-wired Mark II version. I've heard it with KR PX25 tubes and it was sensational if you prefer an objective presentation of fidelity. The bass from this amp is about the tightest I've heard from a triode tube amp and in fact it didn't sound triodey at all -- very much better on the bottom than any 300B. The PX25 is a slightly lean sounding tube, not lush like the 300B on top. But mids are breathtakingly clear, an Audion strength. I'd go with the Audion.
Phil