Being retired from the British loudspeaker business I can state with knowledge that all Satellite-Subbass systems produce a prominent top & bottom which leaves the middle frequency depressed. In fairness to Yamaha (I have the YSTMS50's that came with my 9000Pro) they are a good example of this type of speaker design considering the price point, but can sound a little sharp. To be honest mine have been donated to the bedroom TV and they sound great for that purpose.
Scot keep in mind that even small nearfield monitors are usually heavy well made objects and are 2 to 3 times the price of the YSTMS50's, but as you stated would do a very good job on the board of your choice.

Graham UK