The only EAA Witness gun I've shot is a polymer framed 9mm. As far as accuracy goes, it's on par with my CZ-75. The only reliability issues we had with it were when we were using CZ-75 magazines in the Witness. They fit but didn't want to work right.
My personal opinion from handling the polymer and steel framed guns is that the steel framed pistols are more comfortable in the hand. Not having shot a steel framed Witness, I can't vouch for them in that department, but I suspect that they'll be better there, too. At least for me.
The only problem I had with the polymer framed Witness is that it ejects a little too straight back for me. When shooting this gun, almost every piece of brass out of the gun hit me square on the bridge of the nose. Most of the rest got me in the forehead. I suspect that this is because I am left-eye dominant, but right-handed, and I just had the pistol lined up in the right spot to bean me. Neither of the right-eyed people that fired this same pistol (the owner being one of them) experienced this issue.
We also noticed that brass didn't go very far after being ejected, practially landing at our feet. This is great for the reloader who doesn't want to walk 10 feet for their brass.
All in all, I'd say it is a good pistol and well worth the $350 asking price, though it's not the gun for me.