Gotta agree with Dan001.
I have both Paradigms studios 20s, c-570 center, adp 470s, servo-15 sub and Dali Helicons 400s, 800s and 200 in a 20 x 35ft room. Like paradigms and almost bought the new sig 6s but at the last minute got dalis here and on ebay and could not be happier.
Paradigms are a bit shrill in comparison with the dalis ribbons. Very clear when comparing center channels, the dali 200 center has the same drivers as the 400s. Great mids, softer highs.
A friend has good synergy with paradigm sig 4 and plinius 9200. And Dan is again right when mentioning amp makes a difference. With my Denon 5803avr an cj met1-pre, I preferred the 400s with paradim sub over the 800s. Now with Conrad Johnson met-150 amp the 800s sound much better,much more depth and bass, handles the room. Leaves me content with 2 channel over multi. Dali 400s are easy to drive and have very musical mids and highs, even better with a sub.
Andrew I'll bet your Sim could sound great with either speakers by adding a nice tube preamp, I like the cj hybrid.