I was a going into my senior year at UM when Andrew (cat 5 storm) hit in late August. Lived off campus in South Miami, but only 3 or 4 miles from campus. Although the center of Andrew was reportedly over Homestead, I can tell you for certain that the eye also went through where I was.
As I recall, the wind and rain started to get noticeably bad when it got to Cat 1 and then Cat 2. The TV and radio were still on then and reported the conditions. This was late evening, perhaps around 9ish, may be later (can't recall the specifics.) By Cat 3, TV and power was cut. Only able to get info from the Radio. Cat 3 is also where things got really scary. The worst was the wind gusts which according to later reports, got well over 170 mph. As the night went on, things got progressively worse. The wind gusts came in batches. So things somewhat calm down for a few minutes before the next one kicked off. Then for about 20 or 30 minutes, it was completely calm. That was the eye of the storm. After that, things got bad again. Andrew was a relatively quick moving storm. So by may be 3 or 4 am in the morning, things improved significantly. By 6 am, everything returned to normal and people started to go outside to see the damage.
In the aftermath, trees down everywhere. Projectiles of building materials flew many blocks. I had a stop sign about a block away blew into my yard, so I kept it for souvenir and still have it. Power was out for over 2 weeks in my part of the town. My neighborhood used well water, so no power means no water. Traffic lights were out everywhere, some down on the street (it is huge when you see it in front of you on the ground). Andrew was not a major flooding event, so water wasn't a big issue unless you lived near the water. UM was only back to normal operations after 3 or 4 weeks. Having lived through Andrew, I am not optimistic with Irma being a bigger cat 5 storm and potentially hit Miami dead center. I would advise anyone in Miami to not chance this one and evacuate. I would stay in place up to Cat 2. Anything over that is not worth the gamble.