JS is what you'd expect it to be - entry level instrument on the cheap
X Series - I had a Soloist, sold it. Nothing really wrong with it, but it had a looser, rather rock sound which I personally did not like. On the objective side: Floyd Special, kinda ugly routing, under the neck pickup the spring claw screws protuded into the pickup cavity, the routings were generally swimming pool sized for both the control cavity and the bridge (I guess accounting for less precision). In my opinion this is the worst bang for buck in their lineup. If my experience is any indication of the general quality, it is way too overpriced. Also, some come with better specs, usually the ones that don't have a Pro Series equivalent (at least this is my opbservation).
Pro Series - Spec and build quality wise these are great instruments. For a few hundred extra, you get (supposedly) better woods, unfinished neck, more precise routings, USA Duncans, 1000 Series Floyd(same materials as the Germans, but made somewhere in Asia only for OEM). Minor aesthetic flaws and cut corners, like the clearcoat of the body covering the binding until the neck joint. Of course still no setup from factory.

But my absolute No.1 is a Pro King V playability and sound wise I'd take it over my Japanese E-II any day.
USA - well, you know that.
Most Pro Series are Indonesian. As I observed the ones with Floyd are built by Samick, fixed bridge by Cort (Monarkh for example or the Mick Thomson sig) , bolt-on (Dinky) in Mexico. The X Series I had was Cort, dunno about the others By the way if you catch a serial ISJ= Indonesia Samick Jackson, ICJ= Indonesia Cort Jackson.
The rest is mixed bag, from India to China. They have an overpriced mini-series named the Wild Card series. Excellent specs (German Floyd, Fishmans, what have you), probably made in Korea, but EXTREMELY overpriced. Like 1800 USD...
Also, on a sad note I recently saw a Pro Series Soloist on their website and they forgot tot photoshop the serial from one of the pictures. "Crafted in China". Ouch. For 1400 USD. OUCH!
So in short, X has the looks and can find a great player. Pro Series has everything you need from an instrument, the finishing touches and minor details can be off, no hindrance to performance though. Obviously USA is their best offering. Unfortunately it looks like Fender is getting greedy and driving up the prices while moving manufacture to cheaper places... Oh yeah, I almost forgot they are re-introducing a Made in Japan series, for ridiculous prices...