Here's what I'd say about the Witness, based on the two Elite Matches (10mm) that I have had. They are Italian sportscar guns. They are machines offering incredible performance, and they deliver that performance in a way that forces the user to smile. Many people have shot my Match and declared it to be the most enjoyable gun they've ever shot. The SA triggers are very good out of the box, and can be rendered fantastic with gunsmithing. The only quibble with it is that the trigger itself can have some side-to-side play, but there are replacement triggers that can eliminate that entirely. In fact, for a relative obscure gun (in America, anyway), there is a pretty comprehensive set of custom parts that can be put in. Their accuracy is absolutely great. The big steel frame and outsanding ergonomics makes even 10mm enjoyable to shoot. My Elite Match is my favorite handgun, and only my Beretta O/U shotgun (which cost several times as much as the Witness) can compete for "favorite gun" status.
But. I would not call it the most reliable gun I have ever owned. The guns, like Italian sportscars, sometimes need tweaks. The chambers are generally fully-supported and snug, which makes for good accuracy and an ability to shoot hot loads without blowing out the brass... but they can be slightly finicky with their feeding, since they don't have the gaping maw of a Glock or M&P. I've had an extractor break; it's a replaceable part, but it takes a bit of work. I've had a frame crack; it wasn't in a palce that caused a safety issue, and I got a new gun for free, so they took care of me, and it was after thousands of rounds of 10mm, but it was a crack nonetheless. I've had the rear sight (adjustable) disassemble itself under recoil; again, CS at EAA took care of me, but it happened. Haven't had any issues at all with my 2012 gun, but I've got less than 200 rounds through it.
In the end, I love my Witness. It's my favorite pistol. If I ever get around to actually competing in gun games, I will use it, or another Witness. But it's not my bump-in-the-night gun. Maybe my 2010 gun was something of a lemon (though I loved it until I had to send it back over the frame crack), and the 2012 will prove completely reliable. Then it would be perfect. If it does not, it will just be my very inexpensive Ferrari that is a blast to drive, but sometimes has to be fixed.