Hej,
Mark already said the most things but I want to share my point of view too.
Two kids is not a problem in Germany, though it will be hard in the beginning because everything is different. The live in Sweden is a little bit more relaxing than it is in Germany. We tend to be stressful in all situations. Like shopping. Have you ever been to a Lidl in Sweden? Now they have the same roller conveyor at the pay desks (what the heck is the English word for this?) as all the Swedish shops have. But before that they only had the shorter version, typical for Germany. We don't need the long roller band for the stuff we .. We are trained to pack away the things just bought as fast as possible for human beings.

I still have the feeling at Lidl and they always ask me why I'm so fast and stressed while paying.
But that aside, I love Germany and I think it's a nice country to live in. Some things are probably not as easygoing in the beginning but when you know a German better, they can be real friends. Here it's often more open in the beginning. People are friendly and easy. There it takes more time at first. We often seem to bee unfriendly or rude. But not all of us are
You have to see beyond the rudeness. I guess we just want to complain a lot.

That doesn't mean we're really angry or upset. We just tend to talk . things, other than swedes.
Everything we write here depends a lot on where you're going to live. Germany has much more people even though it's much more smaller. Life in the south is not comparable to life in the north. You could think it's a totally different country sometimes.
The salary should be ok for 4 persons. You have to pay more things like kindergarden. But you don't pay as much taxes. In the end this also depends on you and how you live. What does you're wife? Is she working too? That could be a problem. It's not as easy for a woman to get a job with kids that little. Most women stay at home until the kids are three years old and go to kindergarden. You can find places for younger kids which I would recommend because of the language but it's not as typical there as it is here.
School: More stress and harder for the kids. But I think they learn faster and more. If it's better in the end, I don't know. I'm stressed because they're not so fast here and I sometimes compare my son to kids I know in Germany. But that's not good. The system is too different.
Work: More stress and more to do. No fika and a lot of overtime. Not in all jobs and not everywhere but more common.
But if you have the right colleagues it can be . fulfilling. Bosses tend to be more exact when telling you what to do but they're not used to have so many arguments and meetings like here.
Well. that's it. And there's much more to tell. I lived in Germany for 33 years and I live in Sweden now for three years. I love both countries and I don't know where life is better. Here I sometimes miss Germany but as soon as I would live there I would terribly miss Sweden.
I guess as you're from a nother country, you know the feeling. Every country has ups and downs.
Wish you luck with the decision and a good life wherever it will be.
Best regards
Wiebke