I've been eating Jack's my entire life, and it's one of my go to spots to catch an NBA game, or hang out with my friends at night. It's a great place to share a bunch of appetizers and drinks for couple hours. Servers usually check up on you once in a while, but never bother you too much.
The two times that I've been to this Jack's in downtown core, the experiences were consistent - slow. I've never been to another Jack's that's this slow in my life. It's packed, it's busy, but it wasn't to the point where we had to wait for almost an hour for the food. Our server was running around at one point, and disappearing for a long period of time. Back and forth, and it was difficult to ask for more water, or the bill. I do not recommend this Jack's, go to a different place or go to a different location.