What is your opinion about Heroes IV?

I started playing the second Heroes game a long time ago, then the third one came out, and I played it, then the fourth one came out, and I played it. In other words, I played them all and skipped classes in school to do so :D. Only with the release of the fourth game did I stop going to school. In general, I tried them all. I like the fourth one the most; the interface is simpler, the buttons are conveniently placed, everything is neat and beautiful, the graphics are great, and I think the magic system was improved, and the castles were better distributed. Of course, the AI is a bit dumb. I installed the fifth one, played it, and deleted it; 3D isn't for Heroes :o, and it's not just that...
In general, the fourth one is the best, I just wish there were more XL maps.