B&W DM 640 Tower Speakers- Decent?

A friend has been listening to a pair of Boston Acoustic 2-way speakers with his all Tandberg (early 90’s) gear. His system is good but the speakers seem to be a weak link. I have come across a pair of B&W DM 640 tower speakers in great shape. The price is good to at $250. I am not familiar with these but they look like a solid mid-fi reproducer and would be an upgrade from his current BA bookshelf speakers. 

Anyone offer some insight on the quality and reproduction character of the 640’s? 
5d8015ac 008e 4b30 a925 6dcb77e47c3fvoiceofvinyl
If you can get a pr. for $250, don't hesitate and buy them. They retailed for around $1500 I believe in their day. I owned this spk. and I liked them very much. (Driven by NAD seperates and Vintage Kenwood KA-7100.) I wish I never sold them. They did have different length tubes/and a cap for the rear port. They'll sounded much better than your BA's IMO.