I had the tweeters of my Mission 753 floorstanders upgraded to Scanspeak Illuminator D3004/602000 tweeters in 2014. The original tweeters were aluminium domes which - although they sounded good - lacked refinement, and sounded bright/harsh at louder volumes. More recently, I have been reading many good reviews of the Spendor D7 loudspeakers and wondered if they would be a step-up in sound. (I am not dissatisfied with my pair of modified Mission 753 at all; just conscious that they are more than 20 years old.) To my surprise, I did not hear the expected step-up in sound when I auditioned the Spendor D7 (it was a proper audition, not at a hifi-show). I felt that my modified Mission 753 were in the same league as the Spendor D7; in fact, it slightly bettered the latter in the areas of dynamics and bass, while the D7 even sounded a little bright at times. To be fair, the Spendor D7 I listened to were not fully run-in, and amplification were integrateds (albeit of Rega and Naim quality) rather than my pre-power combination. In other words, I'd like to say you did a very good job of improving the sound of my loudspeakers. Thank you.