My son had this for his 4th birthday. Boy, he loves it! I was a bit worried about how much he would get into it, but wanted to try and branch out from trains and cars. I needn't have worried, he has had so much play with it already. The attention to detail is amazing. I was very impressed with all the bits and pieces that came with it, even down to toy animals to sell in the zoo shop!
None of my other children ever had Playmobil, but can see #3 will get plenty of use out of it, and even his 10 yr old brother enjoys joining in to play with it.
It did take quite a long time to set up though (probably a couple of hours)and Tiddler was getting quite fed up before we were finished doing it, but once its done the first time it is easy to get out and set up again. If you have the space, I imagine it would be great kept fully assembled. We don't have the room however, and in between it gets popped into a box. It generally only takes 5 mins though to get it out and clip it together again.
The thing that put me off Playmobil all these years is the cost. So we clubbed together with Grandparents to get this, and it is definitely worth the money spent.