I've been playing the first few hours via the Origin Access trial period. It's been, well, okay so far.
The game certainly has problems ranging from the conceptual to the technical, of course. There's no denying that. For example, there is no compelling reason for why this game is set in a different galaxy offered by the game. After the opening, you spend less than an hour on a planet before you move on to a Citadel-analogue, filled with characters from all the races you presumably care about. Similarly, the second planet you move to after getting access to the Tempest presents a scenario that would not be out of place in ME1 (Hey SheppardRyder, there's this settlement we have lost contact with near a ProtheanRemnant digsite, could you go check that, kthx); there is just little in the game (beyond the obvious avoidance of the Reaper question) that justifies the change of scenery.
In terms of game flow, one thing I can already see being a tremendous timewasting mechanic is moving between planets in a solar system. In ME1-3, this was a nicely paced process that either didn't take very long (ME1) or had you engaged for short periods (ME2-3); in this game, you're sitting around watching an unskippable animation that takes up to 20 seconds to complete (or at least feels that way).
Once you get down to a planet, the game starts to be fun. The combat gameplay is awesome, taking ME3's foundation and adding in free movement across large spaces, the environments are beautiful, and unlike DA:I, looking at the map doesn't feel like being handed a miles-long To-Do-List.
In technical terms, this is probably the most demanding game I've ever had on this machine (Intel i5-6600k @ 4.2 GHz, an RX480, 16 GB RAM). Using the high preset, framerates were never quite stable until I moved a few settings (Ambient Occlusion and AA, to be precise) down a couple notches, disabled VSync and closed Chrome.
The big points of criticism, however, are writing and animation quality, if the internet is to be believed. Both of these are, for most of the game I've seen so far, okay. However, there are a couple points (which have been pointed out upthread) where there are unforced errors, bad dialogue and cutscenes that feel like they're first pass material that really should have gone back for a few rounds of polish before signoff. These issues are, of course, exacerbated by the general quality level Bioware was shooting for; when your art department spends ages on making skin look good, having people look like weird aliens wearing human skins just doesn't work.
So, overall: Unless the multi is the big draw (and it might be, haven't played it yet), give this one a pass until it's on sale and patches have been made that address these things.
Parenthetically: I would really like to know what this game looked like when they extended the development time. There's bound to be a juicy post-mortem in there.