I played through on normal difficulty, non ironman. I didn't save scum for shots or such but did occasionally reload to an earlier turn or part in the geoscape to correct tactical mistakes I made, more often then not because of interface/camera angle stuff. This was also my 3rd or 4th attempt at playing the game implementing some strategic tips i found based on someone who'd had an early look at the game as well as my own failures. What that meant is I knew what to research and when, i knew which council requests to fullfil and which to ignore.

On the whole while awesome the game started to get tedious towards the end. The ending felt rushed and was explained poorly by gravely voiced etherials. There felt like there should have been another cutscene between interacting with the etherial device and the final mission. Also the last base was a slog, not even a hard slog, just a slog.

I liked the game, I really did but once I figure out some of it's systems and learned the tricks to staying alive and wasn't in such a resource crunch some of the games charm started to wear off.

Annoyances:
The aliens will always get a free move after they see you bullshit: This is the games single biggest problem, especially as the demos seemed to promise that the aliens will be doing things or patrolling or something. Instead they always leap up from what they were doing and take a free move. Depending on your disposition of your troops when you trigger them this can either lead to fish in a barrel from overwatch shots or the beggining of an ass raping as the aliens take their free move and then immediately take their actual move and shot. The reason I don't like this is it forces the gameplay into slog mode leapfrog cover, advance advance, fight, heal/reload resume.
There just aren't enough ships to shoot down! I remember in the old x-com there's this feeling of alien ships being all over the place going about their business. In the current one they seem a rarity and more or less driven by the story. That bugs the shit out of me. Especially since I found myself with more money then I knew what to do with but a lack of corpses and alien nav computers in the late game. Yet I kept getting hit with the stupid abduction missions.
Forced scarcity: This ties into the above. The whole concept that you can't replicate the alien tech is alright to start. I dug ellerium being precious in the previous game as it couldn't be replicated on earth. But now we need corpses too? And alloy, and weapons fragments? All this stuff that no matter how much your research progresses you can't replicate no matter how much money you had. I reached the point where I literally had 2 grand in the bank and very little to spend it on while I waited for a ship to fly over that I could actually shoot down somewhat intact.
ONE TEAM: There was a point in the game when my roster numbered like 20+ soldiers in varying states of development. But once I got more core squad going and got the fast healing benefit out of the officers academy and learned good tactics for dealin witht he aliens there was little incentive to use anyone but the same six guys.
Mind Controlled Enemies Dying Counts as lost soldiers for morale: This little bug got most evident at the end where the mind controlled enemies getting killed by their fellows got me taunted by the aliens. Very strange and annoying bug.