i have the sim audio moon w5. i don't consider it to be warm. it is much too neutral for that. don't forget that most systems include a preamp that could be used to achieve the warmth you are looking for. i don't think it is realistic to try to achieve 'the perfect sound' with only one component change. as if that single component were going to take be the silver bullet and take you to sonic bliss. imo, a holistic system approach that takes into account component synergy is much more realistic.
