I've had two of the 3.
FX9: best ergonomics, most AR-ish if the 3 in terms of manual of arms. Easy takedown.
Mine was a jamming POS until I replaced the buffer and spring with much heavier components. I'd get 2+ jams/double feeds/stovepipes per mag, no matter what mag was being used. The super light buffer it comes with beats the #### out if the rifle, and feels more like a 223. Making it hard to take quick follow up shots. After the buffer upgrade it was pretty reliable. The triggertech FX9 trigger works well in them, but I've read that not all trigger upgrades are safe. The LRBHO rarely worked with genuine glock mags, and the stock charging handle is tiny and crap. The enhanced charging handle is expensive, and barely better. But the rifle is well balanced, and could be a good comp gun with some buffer upgrades.
JRC: bombproof reliability. Thousands and thousands of rounds, not a single failure of any form in mine. More accurate than the FX9 out to 50y, worked fine with a regular triggertech adjustable AR15 trigger. My biggest complaint is the quad handrail. It's big, heavy, ugly, uncomfortable, and ugly. Replace ASAP. Ergonomically it's not all that AR-ish other than the safety. Doesn't have a LRBHO feature, and takes tools to takedown and clean. Luckily they're reliable, so it's not something I worry about at the range. In terms of recoil, the JRC is like velvet, so smooth that its easy to get accurate fast follow up.
Have only held a PC9, it seemed well built but more front heavy than the PCCs I've owned. Buddy has had zero issues with his so far but MCarbo makes upgrades for some apparent weak areas with the gun.
If I was going to get back into a PCC I'd probably pick the Ruger out of the three. It doesn't look super scary, so it may survive the next ban, they're apparently accurate, by all accounts pretty reliable, and they're the least expensive of the three. Perhaps most importantly they're the easiest to find in stock. My $0.03.