Another fairly uncontroversial one. Johnny Mack's is good. Not astounding. But better than okay. I think it's not astounding simply because it's exactly what you expect from any of the thousands of bar/restaurants in New York. All the menu staples (eg - burgers, fries, some pasta dishes, salads, etc). A couple TV's around the place, invariably tuned in to some sporting event somewhere. It's great; it's pleasant; it's what you want if you go to one of "those types of places."
The waitresses and bartenders I've had have all been really, really nice - which goes a long way with me. They don't seem rushed to get your order and take your money; they seem to feel comfortable taking a minute to chat. But not so long you feel your meal or drink's being intruded upon. In that way, they seem to be seasoned veterans of the bar & restaurant service business.
I'd give this a 4-star, but I've always felt like grade inflation is b.s. - so I try to be fair as possible. Looking at the 3 stars, it seems a bit harsh. But if I gave everything 4 or 5, how would you really distinguish the truly great places? There's a big difference between "perfect" and "perfectly happy with." So, Johnny Mack's is rock-solid. I would be shocked if it disappointed. If you want to go with a coworker and grab a drink or two, then sit down to a no-frills but tasty, filling meal - that's the kind of place Johnny Mack's is. "That" kind of place. You know what it's like.