Recently got the S1 Pro. The sound is great. My Taylor is a nylon with a simpler ES-N, so can't comment beyond saying that Bose got it right on all 3 settings (flat, guitar. vocal mic).
My Rainsong with Fishman UST sounds great as well. Reverb is tasteful, to my ear.
Bluetooth/I-Pod sounds exceptional.
I really like the S1 Pro. This has become my go-to acoustic amp.