Broadway theaters are generally exceptionally well kept. The Richard Rogers is an example of an older theater that even though opened in the 1920s has modernized it's lighting speakers and stage related items. However, the one thing it has not modernized is the seating distance from the front of your seat to the seat in front.
My recommendation is get your food and use the bathroom before sitting down if you are in the middle of a row. If you are at or near the end of a row, be prepared to stand up and squish if anyone needs to get out. It's not the most cramped I've ever experienced (that is easily the Ambassador) but it's certainly not comfortable.
Thankfully, Hamilton is one of the best Broadway shows ever, so I think that is why I'm giving it a 4 instead of 3, because once that starts, you forget about everything else.