My E17 just barely drives my Pro's, mind you I drive it with a Colorfly C3 who's output is teh suck... C3 @35/40, E17 Gain 12 & 50/60. There is just enough power in that setup to give a good listening volume. Since I modified my Pro's they are only for desktop use now. So you might want to look into an amp for the E17.
It's like taking a dirt bike up on the highway, it might reach highway speeds but it would be flat out. Whereas something with more power would have power in reserve if you needed it.
I like to have a volume control where 1/2 is a great listening level, with more available for low level sources.
Just my 2 cents...