The remake's method of base management and expansion timing really got on my nerves, I thought the original's method was a lot more enjoyable (ie. if I want 60 scientists, then provided I have living quarters, laboratory space and money to pay for their salaries, I can do that). Playing the remake from the start always gets me down because, for example, I'm stuck with a few scientists until I make an extra laboratory (which magically results in extra scientists), or until I complete a task that gets me more scientists, which I have to wait for, and could also be at the expense of other priorities, and I have to make sure I'm not drawing too much power at the wall... what? Also, the fact that even if you have done all the research, you continue to get more scientists each month who sit around doing nothing and yet cost nothing... I think I had >500 scientists at one point!
The combat element was a lot more fun in the remake IMO, such as the concepts of cover, elevation, etc. Having said that, the original was sometimes more realistic (e.g. the potential for friendly fire). On the other hand, the dynamic in the original for how the enemy could mind-control a friendly unit despite the fact that there's no chance on the planet that they could have line of sight was always something that really pissed me off.
XCOM EW also made some elements of gameplay absurdly easy through upgrades and some absurdly difficult IMO.
The Chryssalid map in XCOM EW was something I really wish could have been a repeating element, that map would have been a lot of fun with some properly tooled-up soldiers.
Overall I'm feeling lukewarm over the idea of a sequel.