A friend of mine has LV speakers (I think OBX's) as a 2nd speaker pair for a smaller room. He used to have a Montille as well and now uses them part time along with a Altec Valencia coupled with a 10W Cortese. His opinion, as far as I interpret his words, is that the 10-15W are OK but not optimal and the speakers need a little more power.
You might check out something like Audio Notes large E Model in HE (high efficiency) version. This speaker runs well even with 5W.
From my experience I can tell that such a combination with a slightly underpowered amp can make enjoyable and relaxed music but on the long run lacks ease, authority and finally musicality if directly compared with more easy to drive speaker.