Hi Tony, I can't help you directly with the Evo 10's since I have not heard them. I haven't even heard the PI-10's, but I would have to question what you heard about them having a glaring treble. The reason I say this is because the PI-10's use the exact same mid driver and tweeter as the PI-30 and PI-40, both of which I own. These speakers are polite, to put it politely. They have a very laid back, warm presentation with very good imaging/soundstage and above average detail. While it is possible that the extra bass driver in the PI-30's and 40's is responsible for the warmth of the presentation, I certainly wouldn't mind if the tweeters were a little bit hotter...and this is using a source and amp considered by most to be on the opposite side of warm with a neutral preamp. In case that sounds like a complaint, it's not. Digital music is infinitely more listenable through these speakers than most others I have heard on comparable solid state systems.
There are three changes to the PI-10 to make the Evo 10...curved cabinet, Monster internal wiring (US only), and tweeter no longer pod mounted on the Evo. In my opinion, only one of these was a good thing and that's the curved cabinet design. Loss of the tweeter pod really hurts this speaker's ability to be tailored to the listener's preference. If the tweeters are a little too glaring, turn them a touch off-axis...too warm, a little more on-axis. That can't be done with the Evo 10's. I think getting rid of the tweeter pods was a concession to those who thought they were strange or ugly, rather than a decision based on sound quality. Anyway, I realize your question concerned how much improvement to expect from the Emerald 93's to the the Evo-10's and apologize for not being able to help with that, but if your mind isn't firmly set on the Evo-10's I would suggest the PI-10's. These are the better of the two speakers, in my opinion, and as a bonus, can be had for considerably less since they aren't the newest model. Hope that helps.
