Nobody knows?
Hi J,
It may be that not too many have gone from one to the other with enough comparisons to post any.
They are very different speakers and "in general" there are some things to consider.
The 626Rs are slightly larger, and heavier.
They probably will both play as loud as you require in a medium sized room.
The greatest difference will be in the soundstage and detail that the ribbons acheive compared to the larger dispersive charachter of the Paradigm.
This will mean that the 626R will have greater detail, sharper imaging, more accurate soundstage, and a slightly smaller sweet spot.
The 626R will certainly be much better for 2 channel serious listening and certainly equal if not better for HT and casual listening.
The Paradigm might be a more forgiving speaker. Meaning that it may mask bad recordings at the expense of accuracy. This is the general nature of higher dispersion drivers compared to more focused ribbons.
While I have heard the Paradigm 40s many times, it was not in direct comparison to the 626Rs, which I have in my current system.
Set up well, driven with quality electronics, (as a dealer and owner) I find them hard to beat in the price range.