They are totally different animals. But, despite that, I consider them both to play in the same class of audio quality. I had the MG111a's for 10 years, then went to the Forests. Not exactly by choice-the Magnepan voice coils delaminated from the mylar panels. They never sounded right after the repair (my work, not Magnepans) so I sold them with full disclosure. The Maggies are alot harder to live with, I now have my living room back with the Forests only 2 feet from the back wall. Never heard the 1.7's, but, to sum it up I would have to say that to the hard core audiophile, the 111a's were a better speaker than the Forest. That doesn't mean I like them better though. They both have their atributes. Power was never a problem for me as the 111a's sounded better with 15 watts of tube power than 300 watts of solid state. I don't think the 1.7's can pull off this hat trick. I do think the Forests are more forgiving of placement and other components in the signal chain. The Maggies were ruthlessly revealing of every little thing... cables, 1/4 inch changes in toe in, placement to the walls, etc., etc., etc. Remember now, the 111a's sound is a bit different due to the true ribbon tweeter as opposed to a quazi ribbon-probably closer to the sound of the 3.6.