1st Order Xovers....A question of absolute volume.

...I spent a couple of nights with a friend's Green Mountain Audio Europas this weekend. I was very impressed with much of what they do, especially for what is really a small speaker. My only concern was with the ability to play loud. Now I don't expect them to match my larger Montanas in output, but what about larger full range 1st order designs? Do they have absolute volume issues because of the type of xover? I am looking at a larger pair of Roy's speakers, the Imagos from the 90s. But I don't want to give up the dynamics and ease of presentation of my SPXs, which have become quite addictive. Any thoughts?

Oz