It's a tough decision for someone who's always been rank-and-file. I had management jobs twice in my career, the second time for about 4 years at the end. It was enough of a pay bump to get me across the FIRE finish a line a couple of years sooner than I otherwise would have. But the added stress might have taken a couple of years off of my life. ;)
Here are a few things to think about:
You'll likely be working a lot more hours, and getting paid $0 for the extra time. You can't bug out if your staff is still there plugging away on an urgent project, even if you came in earlier than they did and put some time in last weekend.
Can you pull back from the nuts-and-bolts work and give your staff just enough guidance so that they can do it right? It's tempting to just push them aside and do it yourself, but you can't do that, because it destroys their morale. And you don't have time to do their work plus yours.
A good boss is an advocate for his/her staff who makes sure they have the resources to do their work, and also that they have support when they are in conflict with other staff groups or managers. But you can't just be a blind advocate. Sometimes your staff is just wrong, and you have to tell them that without crushing their morale and turning them against you. Once they start to dislike working for you, the situation has turned dysfunctional, and it is very difficult to turn that around. To please your boss, you ultimately have to do what's best for the company bottom line, which may or may not always be what your staff wants. It's a tough balancing act.
One of the most important things you can do to support your staff is to make sure that their achievements are recognized and incentivized. You'll need to make time for this, and you'll need to be willing to sell your boss on it.
You will spend a lot of time on performance plans, performance reviews, counseling staff, and making sure they have the training and resources that they need. If you don't spend a lot of time on these things, you're doing something wrong.
How do feel about meetings, phone calls, e-mails, and text messages? These tasks will fill your 8-to-5 hours, and any quiet time you need for focusing on other tasks likely will get pushed outside of the 8-to-5 time frame.
How do you feel about disciplining your former peers? Sooner or later you're going to have to do it.