I have a Prosonic 2x10 combo and it's a great amp but my experience has been that it really comes alive with a 2x12 cabinet. To me, it really needs the 2x12 to compete. Obviously, this is personal taste and opinion. With the head version and a 2x12, great for country/classic rock. With a few pedals it can get you most places.
No experience playing the Supersonic.
I've used a friend's Mesa TA-30 and it's quite versatile with a little work to dial in your sound. Not what I would call "Fender cleans" but a very nice amp. I do like the gain from this amp more than the Prosonic.
Although the Prosonic is not traditional by Fender standards, I still say that's the sound you can expect from this amp.
With the Mesa, a much more modern sound.
Either one is a solid choice. I would say trust your gut on what you usually like, Fender or Mesa. Although these amps are a little bit of a diversion from what they typically make, they still hold true to the Mesa and Fender traditions.