I have heard the Sopra No3's but at a show, not a great audition, music was too loud, lots of people in the room, music I wasn't familiar with. It seemed that the No3's had a little more bass impact, but this was not an ideal way to do an audition.
My dealer let me know when the No3's were first available, but I think I'm "set" with the No2's. I suspect that either would bring a smile to your face.
As for subs, in my opinion most "main" speakers don't compete with a good sub in the low bass region. Having said that, I'd recommend you take some quality time and audition both models. Though I enjoy having subs, the additional bass from the No3's might be more pleasing to you, than struggling with properly integrating a sub (or two). In my experience, it is sometime fairly difficult to get subs to sound good, based on the individual room acoustics.
Happy Listening!
