I've only seen one STI with function problems, a Trojan thaw had feed issues, but thtat may have been related to the owners reloads.
I had a second hand P16-40 that would not extract and occasionally would not feed. The swinging link was peening as well making it hard to work the slide.
I've seen a P14-45 with a cracked frame, a brand new Para that had to have the mags replaced with STI mags to get it to function, another with the same problem that functioned well, but over a year of IPSC shooting _all_ the internal parts wore out and had to be replaced with aftermarket bits. I've also seen one where the rear sight came loose.
As a result of the above I am not interested in any Para Ordnance product.