Wouldn't it be more efficient to comment on the speakers that wouldn't be good econowave candidates?
Really -- they guy has just barely listened to the speakers, the tweeters are fine, and he likes them, and already with the econowave suggestion?
Don't mean to be cranky, and certainly a speaker with bad tweeters or a lousy high end might be a good candidate, but many people like the differing personalities of speakers, and if they are all econowaves, not only is that personality lost, but so is much of the history. And, perversely, given that econowaves quite possibly are better (in an absolute sense) than the original tweeter, and much more expensive than leaving it alone, the value of the speaker may be less after the conversion.