"At least you know what you have .....". Yes, nothing that remotely resembles the air, openness, dimensionality, harmonic structures, etc., of the series 3.
I owned the 3.3 and 3.5 for a combined 6 years. Everytime I went to the Magnepan dealer, the series 1 speakers, and the series 2 speakers for that matter, did not come close to convey the musicality of the series 3.
At the used price of <$2k, the 3.5s has virtually no competition. The one unfortunate issue here is that these speakers require a lot of money invested in an amplifier for the owner to hear its true potential. There's always so much focus to use Bryston amps with these speakers, and this was true for the dealer here too. But the Bryston is mediocre at best after hearing these speakers on so many other amps in the 200-400w range. These speakers sing magic with tube amps.
An excellent starting point is the Counterpoint SA20/220 or NPS 200/400 amps. Then if you can, try to move up to the VTL 450 or Wolcott P220 mono amps. Or if you want to stay with solid state, perhaps an older Rowland or McCormack 225 might just do the trick. The 3.5s driven by any of these amps would destroy the 1.6s driven by the best amps in the world.
John