I have a Simaudio i-7 and am looking to upgrade to some combination of Simaudio P-7/8 and W-7/8. I just bought a pair of Revel Studio 2s and they are a fantastic match with the Simaudio i-7. Before buying the Revels I auditioned a whole bunch of speakers with my i-7, including the Sophia 3s, Sonus Faber Cremona Ms, PMC PB1i/OB1i, B&W 802D MkIIs, Usher Dancer 8571s and Monitor Audio Platinum PL300s
Personally, I preferred the Revel Studio 2 - Simaudio combination over all of these speakers. It was preference, though. Reflecting on all the auditioning I did there was not one speaker that I could say the Simaudio i-7 didn't work with. It let the characteristics of each speaker shine through and, in the end, my choice was based on the speaker I liked the best rather than the pairing, per se. I'm only now looking at upgrading from the i-7 because others have said that I'll get tighter, more detailed bass from the Revels with more power. Nothing wrong with the way they sound but we'll see if I'm missing anything!