Michigan Mike,
I am 59.5 years young and have had many speakers over time and the Maganpan's with a 5ft or so ribon tweeter was probably the most awesome sounding tweeter I ever had the pleasure to own and listen to.
But I have had other speakers like the 1988 Classic Mirage M1's (185 lbs each and 5 ft tall). That had dome tweeters that were in the same league to my ears.
If you have had the chance to AB the SongTowers at Jims etc with music that you are familiar with and like then the choice to you should be discernable.
If it was not then theres another data point....
I thought that when I listened to jazz with like Jazz at the Pawnshop the vibes were magnificant...compared to a dome tweter....better how...I guess its the sound and what my mind is conditioned to believe...something so light, so thin, so low in mass has to be able to react faster, quicker than a dome tweeter????
But when listening to this disc over and over and comparing to different tweeters...there is a difference in sound and how it 'sounds' to me....and I preferred the Maggie's ribbon sound better than the dome tweeter speakers I had back then.
But the ribbon in the Maggies was quite large compared to the one in the SongTower that Jim makes. I dont know if this would make a difference, I dont think its fair to compare a 5 ft ribbon to a small dome speaker
So my gut tells me that in the Songtower comparison between relatively same size tweeters ribbon and dome..that they proabably are close and you would be happy with either....I would probably think the ribbon would win out if I had to really compare the two..
With all that said, I have a dome set on order!! So there ya go.
All the Best
Alex