I'm a primary school teacher, qualified to teacher 4-11 and currently working in reception, so hopefully I can help a little! I will try to be as transparent as possible.
The holidays are an undeniable plus, but just a heads up I usually spend at least a week of summer holidays (last summer we had five weeks, because of inset days) in school, preparing the room for the children. That's not including planning time, shopping for your class (from your own pocket), learning about/researching the curriculum you will teach that year ect...
During term time, I get in to school for 7:30 and leave at 6 most night, later if it's a staff meeting night. This helps with not having to take as much home, but especially during data and report season I can be working until 10pm and I usual work for around three hours each weekend, and then have to resource shop also for things the children need in class the following week.
In the day, I struggle to get everything done with the children that needs to be done, the expectation is very full on even for tiny humans, and sometimes you feel like a villain because you're pushing them to work. But you just have to make time for as much fun with them as you can!
There is also the abuse from parents, the tragic instances of neglect you will see if you work in an inner city school like mine, the lack of funding and support that often means you end up with lots of children with special needs and you can't give them the 1:1 time they need, because there isn't the funding. Makes you feel immense stress and guilt, at times which isn't great. But also, you have the chance to reach children and show them love and kindness.
The pay is fair, but questionable when you consider the hours that you will be working. The pension also takes a huge chunk out of your salary each money, around £200. Just something to keep in mind. Also, a lot of schools can't afford to move staff up the Payscale.
You will also have to listen to people harping on about the amazing holidays and the 9-3 hours (we wish!)
But I can honestly say the satisfaction you will get from working with children is amazing, but this and only this is the reason you should enter the profession. Poor work-life balance is the reason a lot of teachers leave, it is manageable but you have to be so very strict. For me, it's the emotional strain I find that has the biggest impact on work-life balance, rather than paperwork - it can be tricky to switch off, evenings and weekends the job is always at the front of my mind, and you have to be mindful not to neglect your own family because of that.
It's not all soon and gloom, I love my job and wouldn't do anything else. But I recognise it's not for everyone.
Hope my honest account helps you make an informed choice. Best of luck with your decision, and if you choose to join us then lucky you, you will have the privilege to shape young lives.