What are you preferring in the old ones compared to the new ones? I have heard both types that you have and I preferred the old ones actually as I found the new ones to be too "in yer face" (could have been amps as well). Looks like the midrange driver is different (at least based on the color). AFAIK, the tweeter is still the Beyma CP380m, a great tweeter.
I doubt the current Duo XD uses the Beyma tweeter you mention as it's shown as 8 ohms whereas the XD Duo has an 18 ohm tweeter - and mid for that matter.
I don't find the new speaker "in-yer-face" although I know exactly what you're describing. In fact it was because I found my old ATC50 Active speakers so in-yer-face I wanted to push then 20 ft further way. I looked around, read Robert Deutsch's Stereophine review of the Unos and bought a pair in 2002. Suddenly music opened up with clarity, detail and excitement that I'd not heard before. I changed the Unos last year to the 2006'ish Duos (not Omega spec) and bought the XDs a couple of months ago.
No, I find the sound quality much the same. The XD uses the same mid and top drivers as the earlier Duo Omega. The difference in sound is relatively subtle. Now the XDs are broken in, I'll be doing some A-B testing using a switcher to select the speakers without leaving my seat.
It's the height of the XDs that require them to be tilted forward to obtain the recommended presentation towards a typical listening position that I don't like. This looks ungainly from the side in particular which is very noticeable in my room. They needn't be that tall as the older Duos have deeper cabinets than the XDs. With the bigger 12" drivers the cabinet could have been made a little deeper and less tall to achieve the internal volume needed. You can always jack up speakers but you can't shrink them!
Also, as you'll see from the photos I posted, I don't like the vertical "scaffolding" that AG uses on the Duos. I ditched these 3 poles in favour of a rear-mounted F frame that supports the horn tubes and this makes the speakers appear much "slimmer" and less fussy - a feature I was looking for as it blocks less of the view from my windows behind the speakers. I'm planning to do something similar with the XDs.
I've not got to grips with the XD software. Unfortunately AG don't offer a facility to measure the speakers before making the comprehensive changes that the XD software offers. It would cost little for this to be included with the XDs (as it is with for example Martin Logan hybrid speakers), so I'm a little disappointed that adjustments have to be made entirely based on what one hears.