Having now started it up a few times - I can definitely say that it is a misfire - all the way through the rev range - not just rough idling.
And still no check engine light coming on.
When you start it up - that initial higher about 1500rpm idling that it does is fairly smooth (well, kind of..) - as soon as you touch the throttle, it starts missing and chugging - and as mentioned, warm idling is down to about 500rpm with lots of misfiring and wanting to stall.
When they swapped out the solenoids, they did lift the coil rail out of the way - but after everything was put back, the car ran just fine - better than ever for about 3 days - no issues. So, I don't get what suddenly happened.
The new spark plugs have been in for a while, don't think they used the wrong ones.