Hello, I have not heard the AAD C800i speakers but, I have a pair of Soliloquy speakers that I really like. They are both designed by Phil Jones. Phil Jones is famous for designing speakers for Platinum, Boston Acoustics, Acoustic Energy, Soliloquy, etc. Phil Jones actually moved to China and lives over the factory floor to maintain the quality of the components. Phil designs and specifies all the materials used in his speakers (tweeters, woofers, crossovers, cabinets, etc.). This way he can achieve the sound that he is looking for. It is easier to design crossovers when you have designed the other speaker components (Synergy). Phil's speakers are typically very heavy for their cost. As a rule, I generally like a higher weight to cost ratio. Phil's newer speakers are also usually very sensitive 90-91 db at least. This high sensitivity will allow you to use any tube or SS amp to power them. I think that they are a lot of speaker for the price. Look on the Soliloquy website for more information on the AADs.