No experience personally.
However I wouldn't say sell your controller in favor of this yet. I mean out of the box it can control pH/Temp/ORP as well as trigger stuff via switches (floatswitch for instance), and of course anything you plug in that requires a timer to do something. However the benefit it has is that you can expand to MANY more plugs (at a cost of course

) by buying another PC4 module (4 plugs), and there's always future developments that make it quite expandable potentially.
However if your ACJr. is doing everything you think you would need, don't get rid of it.
I think Bryan and I bought this because it's our first controller, its not that much more than an ACJr or RK2 if you add in the probes, and it is cheaper than an AC3pro that doesn't have probes. Since I won't know what sort of stuff I'll need to do in 5 years, I like the expandability of it. I mean I've seen a few people locally sell off their ACjr because of it's limitations when something like wavemaker module came out (not enough programming space for it), while yes add-ons won't be free I'll know I don't have to sell my used baseunit and buy a newer more expensive one just to play around with the stuff.