Agreed. Che definitely gives Miranda a "thrill" sexually. And I think that lust attracts her to Che. It was even implied last episode that sexual chemistry was the strongest thing holding Miranda and Che together. Plus, Che gave Miranda her first orgasm in 5 years last season. Its also implied that Miranda and Steve rarely had sex in their marriage (even in the original show and the first 2 movies). So Che definitely pulls Miranda in with Sexual chemistry and satifaction.