You are going to live with the speakers so what you hear is what ultimately matters. Listen to a pair of 1.6's and any pair of 3 series maggies(IIIa,3.3,3.5, or 3.6) and decide if the coherence of the 1.6 or the true ribbon of the 3.5 is what will float your boat. I own both the 1.6 and the 3.6. The 1.6 was my main speaker for four years and the 3.6 for the past two which I upgraded to when I was afflicted with "what if" disease. Both are great speakers and have different strengths and weaknesses which the previous posters have covered in depth. I am happy enough with the 3.6 as my main speakers and I was happy with the 1.6 which now serve as surrounds. I confess I have not done a shootout between the two because if the 1.6 wins, I will have to go to the trouble of selling the 3.6's. And I just don't want to deal with that hassel.
Which Magnepans 3.5 or 1.6?
I am looking to purchase a set of Magnepans. My budget is about $1800. Would I be better off with a new set of 1.6QRs or a used set of 3.5s? I am using a CAT SL-1 mk 2 pre, Resolution Audio Opus 21 cdp, and for now an old Bryston 4B amp. My next step will be to replace the amp.