I listened to 1.7i in a showroom paired with a Mac (cannot recall model). To my ears, I was a little disappointed in some sound aspects, particularly the lower octaves. I’ve had a different dealer tell me that isn’t uncommon with Macs. Prefer my Plinius.
That said, I agree with others that - space/room allowing - upgrading to a true ribbon model will be far more impactful than an amp upgrade.