If you go for the 300, note that the difference between MK1 and MK2 is a tighter bass response on the mk2 while the MK1 has more bloom and less definition in that region.
Oh and speaking of stand mounted the old Grand Coupe is a bargain if you want to cut costs.
I have not heard the Ikon 6 in any controlled environment, so you are on your own there
I've heard lots of Dali speakers, anything specific you want to know?
A few notes:
The Helicon line is the sweet spot price/performance wise, especially the 300 stand mounted.
A lot of their speaksers have a sort of mid bass hump.
Old gems include the Dali Grand Diva and of cause the Megaline