So I've put in about 10 hours a day into this game since it was released and I wanted to share my thoughts:
First, I've found it quite engaging, and would be satisfied with the time and enjoyment I've received from it. My favorite mechanic is the hero-leveling and adventuring and have found that portion of the game quite compelling.
It takes approximately 4 hours for me now to get a band of 2-6 heroes (who I keep in a single group because experience isn't split) up to the mid 20s in level. I can then split them out and have them mop up the rest of the map with ease. This is playing on large maps and normal difficulty. Unfortunately, reaching this point consistently has kind of burned me out on the game, but I look forward to diving back into it after a few more patches.
On the downside, and as I've stated in other threads, this hero strategy which is so effective it completely negates the need for technology or cities. Heck, I play with a scholar hero and a race with +10% to research and use the fast research setting and I still never get to a point in the technology tree where it's remotely useful. Getting horses is nice, as it helps out my heroes, but regular armies are absolutely useless. I wish magic was a bit more varied and interesting. I wish technology at the fast setting moved about 4 times as fast as it does. I know the AI is going to get better.
I believe this is going to be a magnificent game upon release. Thanks Stardock!