I am a Primary school teacher and I love love love my job, can't imagine myself doing anything else. Having said that it is a tough job- it often feels like the responsibility never ends, I am always wondering if I am doing enough, thinking about what to do next etc. Work load can be really full on- when I was first out (before children) and teaching my first class I would get to school by 7:30- stay till 4:30 and do a minimum of half a day on the weekend as well a couple of hours at home in the evenings. Now that I am working part time, and I am a bit more experienced, obviously not putting in as much time- I can't, I have a family now and it just would be fair on them. I find report/ assessment portfolio time to be very stressful, It takes a lot out of me but usually only lasts a few weeks.
Dealing with troublesome students & parents can be quite draining, but usually if you have a good Admin team, it cuts down on that stress as they take on alot of that work load- at the moment in my class I have a couple of quite severe behaviours and it is draining, but my Admin team is working hard to support me and get me some extra assistance with those students.
On the plus side, and for me this far outways the negative, I love the challenge of finding fun and creative ways to stimulate student learning- I am by nature a thinker, and I am often coming with activities and lessons that even excite me. I love the bonds that I get to share with my students, and the progress they make over 12 months. I love all things school, I love assembly items, and school concerts, book week parades etc, I just love being a part of that environment.
The biggest thing for me when I got into teaching was, that if I could change the course of just 1 child's life (for the better obviously ) because of the time they have spent in my classroom then I have made a difference to this world, if I can do it for more than 1 child then I am a lucky person, because to have the power to change lives is both a wonderful and scary thing and if you are passionate about what you do, and you and you can foster a positive attitude towards school, and love for learning then you are really great at what you do.

Good luck with the decision, I say go for it, but I am biased because I love what I do so much.