I read elsewhere that the new engine has most of the vibration issue solved with a counter balanced crank...a totally new designed crank...Dick has made a most valid point, as usual.
I remember a close friends 33% H-9 Suk some time ago...had the ZDZ 80 in it...sure, he had extra lead added to the firewall for balance...but when he replaced the zero problem, never a hiccup, ZDZ 80 with the DA-100, he clearly lost some wing loading, and what I would describe as it lost some exceedingly s-m-o-o-t-h responsive flight characteristics, and truthfully I never saw him fly that plane as well, or the same ever again.
It was never under powered as it was, he said he liked it w/the 100, an yada, yada, yada, but to me the proof was in the way that plane flew, or the way he flew it, sorry I'm unable to explain it better, but I have a feeling many of you get where I'm coming from.
Perhaps it was better balanced....I mean w/the 100 it was an animal, sure.....but it just seemed to be a thoroughbred before...and a definite wild thang after the swap.

I personally never saw evidence of vibration so bad that an explanation was needed or asked for on the ZDZ80.
I have been until now resistant to move to the 33-35 % class....the whole double tuned pipe, canister hack up the cowl thingy never gave me warm fuzzys enough to make the jump.
My experience with the DA-50 has committed me to Desert Aircraft anyway, I am truly glad they picked it up a notch in the direction they went, with the 85...