I've owned both, but a couple years apart. I had a I-5 for a year or so and loved it. I was driving a pair of Hales Rev3s which I still have. Source then and now a Musical Fidelity XRay. Cables now are Analysis Plus Silver Oval ICs and Cardas Cross speaker cables. I now use a Llano A-100 amp and an AES-3 pre. When I compared the I-5 to my present rig it was a tough call. but I guess I liked the little bit of tube sound I get from the pre. I recently picked up a Classe' CAP150. Again I compared that with my current system. The Classe' excells in the bass, but seemed a bit too much in the highs. Again a judgement call. I have not had the Sim and the Classe' head to head, but I think I would like the Sim better in my system. And I am about to put the Classe' up on A'gon as soon as I can get some pic's. Good luck, both are excellent units.
Happy Listening
Woody
Happy Listening
Woody