[Ruminant]

Well, the combat -is- almost exactly the same. Its the same hex based two sides lining up and beating the crap out of each other. In my opinion though its much more fun. Mostly because in HoMM combat often devolves down to 'whoever has the most troops is gonna win'. In this you are hard capped in the number of troops you can recruit, and can only slowly increase that by leveling/finding items. Winning against numerically superior foes, which are quite easy to find usually, can be done by utilizing your troops abilities (theres way more variety in abilities than in HoMM and most creatures have more than one) and thoughtful use of spells and choice of creatures/items that synergise.

As for leveling, I like the new system. It gets rid the random element that could sandbag you with abilities you wouldn't really want and lets you build your hero the way you really want.

It's all subjective of course. You might hate the fact that base building, the struggle for map control and logistics (trying to get your creatures to where you need them on the map at the right time) has been blown out the window, I love it.