As you say you've been a Stardock player in a past, a good analogy is the original vanilla version of GalCiv2. Huge step forward from its predecessor ( Elemental:WoM in this case) in terms of getting a strong foundation and getting most of the little things right. It needs a bit of polish in terms of bugs & balance but so far those are not detracting from the fun for me.
Not sure what level of detail you're looking for in how it plays? At the very top level summary, it's a mashup between an RPG and a 4X empire game. It would stand on it's own as a good 4X (if not quite on the level of the all time great 4X games that some of the dev team have been a part of). The tech tree is pretty well put together but quite straightforward and sorta short; diplomacy is serviceable but not a strength; City management is interesting but it is lacking some layers of complexity of the best dedicated empire games. Let me say though it is a HUGE step up in this department from the original Elemental, or from Paradox's Warlock, or from not-really 4X strategy games like Heroes of M&M / Age of Wonders. The world is (by design) fairly desolate and random maps can be "unfair", in a way that veteran players of other games may find a little bit off putting at first. But it doesn't seem to actually deal too many really unplayable starts, and once you get used to it, it can be refreshing compared to the perfect grid of profitable cities and suburbs familiar from, say, Civ. Here, can really feel good and rewarding to find a fertile valley big enough to support 3 cities, and then you have still to scramble your scouts and rangers to the hinterlands to find and clear any more lands in the wilds beyond.
The campaign is solid but short. Don't expect to put 60 hours into handcrafted scripted scenarios, the way you would in HoMM / AoW. Bulk of your time will be in sandbox games on random or perhaps custom skirmish maps.
The role playing elements mixed in are what really give it the potential to make it a really unique experience. These include special wildland regions around the world, kill & fetch quests found in the conventional way from inns and huts, random events, and just good old fashioned exploring the countryside and clearing monster lairs. How much you personally find the mixture of 4X with RPG to exceed the sum of its parts probably determines what you think of the game.
Now, once you get really into the game and put some hours into it you might think there aren't quite enough unique quests or items implemented yet. So, the role playing elements may get a little bit repetitive on multiple playthroughs, but in an endearing way, sort of like running every new Morrowind character around Balmora to pawn the Blades' alchemical equipment. The RPG part of the system, well, it's not exactly Planescape:Torment, but it's pretty solid. At first your heroes can barely strangle a sick 3-legged hyena, but every time you kill enough enemies you get a stat boost and choose 1 from a set of 5 perks. After a while a hero can become a match for 20 men in combat (as long as your empire can provide you the tech for good gear and coin to buy it), or a match for 200 men via magic (at least until you run through your empire's mana reserves). Your heroes will also need to rely pretty heavily on support from squads of mundane troops, either as elite fighting partners or at least as dragon-fodder. The balance of power between heroes and armies here seems much better than in the original E:WoM.
Combat is quite good if you think of it not really as a tactical game in its own right but as a extension of the strategic game. So, there are not tactical decisions like facings, altitude, cover or line of sight; but rather you do micro-manage strategic choices like how much mana to expend and to deploy your armor piercing weapon squads against relevant targets.
Most of the negatives I touch on here I think are things that can be eventually addressed with some kind of add ons. The core features are in good shape. Therefore I'd say that it is at least *possible*, after a couple of expansions/mods which up the complexity and replayability, to make it an all time classic. Standing on it's own merits today i'll give it in the neighborhood of 8/10.
