It's probably heresy to talk shit about Long War, which is seen to some as the TRUE XCom experience, but I disagree.
One of the main issues of the modern Xcom 1 was the lenght. Near the end of the game cleaning enemy ships was more of a chore than a challenge, but you could still be wiped if you alerted 2 enemy pods at once.
Long War raise it to eleven making the campaign even longer. I like Xcom a lot, but there is such a thing like too much of a good thing.
On a smaller basis, Long War crew did their best to remove any cheese from the game, which is another way to say you have a specific way to play the battles. Personally, I think finding and exploiting AI flaws part of the fun of strategy games, but it's just me.
Even fans of Long War will praise it saying it's long, hard and wearing. I'm not fan of the casual mindless games, but I prefer it to a test of patience.
This said, Long War has options to make it more friendly, like «Not-so-Long-War» and «Friendly Skies» which make the whole thing far more enjoyable so there is that.