The two are really very different, both are excellent but in their own way. I have heard duos extensively and the big issue is getting them set up properly. It is not easy and if they are set up poorly, or even just ok, they will not sound their best. The new omega is a big improvement as far as an upgrade but expensive (though cheaper than new speakers). The duo sound you know but it is very dynamic, as befits a horn. If they are bright up top it may be the ancillary equipment or your room, classically it is not a problem with them in my expereince.
The wilson sound is much different. I have friends with wilsons and those that like wilsons, like them period. They also tend not to like speakers like duos. I have other friends who can't stand the wilsons. It sometimes takes a bit of listening to figure out which group you fall in. Its not that they are bad at all just a very different presentation. Wilsons also need proper set up but as a whole I suspect they are more tolerant than the duos.
Since it is always cheaper to fix your current system than buy new stuff I would suggest make sure proper setup, consider your room acoustics and the ancillary gear. If those are not remedial then by all means audition the wilsons but try to listen in house with them.
Good luck
Gary
