I have EFX front mains and rears and won't go back. I purchased them from an AVAD dealer for $2600/pair new. They have exceeded my expectations probably because my room is only 10x13. They get louder than I want to play and I run them with an integrated amp NAD T787 no sweat. It has not shut down in protection mode at my volume levels. I cannot tell a difference over my separates although I have no way of A/Bing them in a controlled way but can say that I don't know why anyone would need more power in a smaller room like mine at my listening levels. It is simply unnecessary plus the NAD doesn't overheat even within the unventilated cabinet which is a benefit to driving them with more than enough power. Good luck putting your Onkyo in a cabinet. My watt consumption went from 240+ watts with separates to 130 watts integrated. The EFXs are bolted onto the side wall leaving at least two feet from the front walls and are 9 feet apart so it worked out perfect.
The only problem is, when you're on the couch, the panels are not ear level. These either need to be bolted lower like a few inches from the floor (which will look weird from a design/aesthetic standpoint or you have to flip them upside down so the middle of the panel is ear height. Currently when I stand up, the volume gets louder and I hear more details which is a little frustrating knowing I'm missing out on 10% of the performance.
I used to think that since ML designed these as surrounds in mind, they probably wouldn't make good mains, but remember that they have the same panel area as a source which was intended to be mains and people love them. I believe they have the same panel area as the script-I as well but is better quality with updated looks and tech.
I don't miss my Spires after blasting one of Diana Kralls Jazz CDs on it. They retain the electrostatic sound but with a very small foot print. Sure you can get a full range cone speaker for that price like a top of the line Klipsh RF7 but after the demo at best buy, they were nothing but loud sounds like any other typical mid grade brand and leave a huge footprint which was my original concern. Basically, the sound quality was so good that I now understand why ML owners dislike DSP sound fields. basically, these speakers are a ML Source with a smaller woofer.
I believe a lot of the EFX price goes into the application specific purpose and lower sales volume but I'm sure it will blow away anything of this footprint. As for price , I'm sure it's better with the exception of dynamics of certain types of music. I think that is obvious.
Watching the new Silent Hill on these with a ML sub and MotifX center tuned with just XT was really good and got better the more I turned it up probably due to the fact that the 120watt FDC rated amp was not stressed/clipping. Although I don't have a system to compare it to, the sound quality was apparent. Tons of surround information constantly as if the surrounds could be mains which makes me believe full range surrounds/matching does have benefits.
I'm not sure what is better between the Spires woofer integration and the EFX with subs. I have not AB'ed them but an external sub will require more tuning/placement. Because I have to run a sub, I use the sub as a drink holder so I don't lose footprint savings over the Spires they replaced.
