Line Magnetic 219ia vs. 518ia

I have been interested in the difference between these 2 integrated amplifiers from Line Magnetic for a while now, and thought that some members might be as well. Given the difference in their size and price, and the very enthusiastic review of the 518ia by Herb Reichert in Stereophile, I was hoping that the difference would be minimal. That was not the case
I went to audition both amps this afternoon at Arizona Hi Fi on a pair of DeVore 0/92 speakers with  Luxman CD player and Nordost Odin interconnects (!). Both were fully broken in. First the less expensive 518ia. Sounded good, not great. A little harsh almost on some loud sax breaks, but then again, I never heard these speakers before. PRAT, which was highly touted in the Stereophile review didn't seem any better or worse to me than what I get from my Audio Note Kit1.  Listened to Jazz, Cream, Jethro Tull and Squeeze.
Next up was the 219ia. Instant difference, no need to lean forward and squint. Very obvious that there were 300bs in the circuit. Smoother, much more layered, detailed and refined. A real wow moment. Listened to all of the same again and was very rewarded.
I love my Audio Note but have been considering a change because besides my horns, I have small inefficient monitors that I would like to use occasionally. Both amps had very good bass reproduction due to the 845 tubes. The reason I felt the need to write about this is that in one of the major reviews of the 219ia, the reviewer compares the two and seems to say that the difference isn't much and that he'd be happy with either. Not me. There is a very big difference.
The dealer also had a new amp not on their website, the 508ia which uses 300bs in front of 805 tubes and some 6sn7s I think. I didn't have time to hear it today and the salesman was tired of lifting!
As an aside, I finally got to audition the Sugden A21 class A integrated on his recommendation, and that its a great little amp. As good as the 219ia? No, not quite as colorful and a little bit drier on the top end, but excellent musical sound in most ways and a great value.
I thought that I would want to keep my Audio Note no matter what else I might buy, but if I buy the 219ia, I can let the Audio Note go. It's a great amp.