I have owned both the Aerius-i and Abby and they are very different speakers. The Aerius-i required a lot of power and had a difficult impedance curve. I drove them with a Bryston 3B or Audio Research VT60. The VT60 sounded much better in my opinion, and would drive them very nicely, but you could probably fry an egg on the output transformers due to the power demands of the Aerius-i. The Abby on the other hand are very efficient and easy to drive with almost anything, but they are much more critical of amp selection. Also the Abby doesn't have much bass and that is why they were intended to be used with a Sub (Bailey). I believe you would find the change from Abby to Aerius-i very pleasing if you have the amplification to drive them. One thing I would caution, however, is the sensitive and delicate nature of the electrostatic panels on the Aerius-i. With my pair, I had 1 panel sounding weaker than the other. Due to the age of the panels, ML suggested replacing them with new ones. They are only sold in pairs and they are very expensive $$$. I replaced the panels and played them happily for a year or two. When I sold them, the guy listened to them at my house and they were working 100% but when he transported them home and connected them, he said one speaker was weaker than the other. I would just caution about the delicate nature of these electrostats of this vintage. The new ones may be more robust. Incidentally in my opinion, I liked the Aerius-i better than the Magnepan MG1.6's I had, but that is just personal preference.
