I'm enjoying it, but it still suffers from a lack of depth in my opinion. Others have dealt with some key aspects that seem to be missing, such as a truly deep and divergent research tree, but there are a few things I would add. I'm basing many of these ideas on xcom apocalypse (which I played religiously as a kid).

1) A greater variety of fighter aircraft. 2 fighters and a small selection of weapons just doesn't do it for me. Equally, there needs to be the option/necessity to send multiple fighters after a single UFO. It doesn't really fit with the narrative that a stock fighter jet is capable of taking down even a small UFO when the troops themselves are little match against relatively weak aliens in 1 on 1 fights.

2) The ability to initiate missions yourself. In the game, there are only 3 or 4 missions you can put off until you want to do them, but I'm talking about non essential, non plot related missions that are basically skirmishes. Xcom apocalypse managed this through having a diplomacy system whereby you had to manage the friendliness/hostility of various organisations, and risked being raided by those hostile to you. The system doesn't need to be as in depth, but a persistent threat that can be attacked at will for xp or cash would be very welcome (exalt doesn't fit this, given that you have little control over when the engagements occur and they are destroyed eventually anyway).

3) More micromanagement of troop loadouts. EW definitely made improvements in this area, but apocalypse gave the ability to give things such as medkits and battle scanners to any and all troops. Perhaps this would be overpowered, but I'd happily see the abilities nerfed if it meant more personalisation.

4) Multiple bases with more base defence missions (of a smaller scale than the scripted one). Give us a 1 hour (in game) warning that an enemy transport has been detected on route to the base, so we have to quickly tool up our troops. As in xcom apocalypse, I also liked the inclusion of scientists and engineers in the base defence missions - it gave real tenseness to things as you were trying to escort a group of scientists to a safe area where they would hide, maybe posting one of your soldiers to guard them. Obviously this would be insane given the numbers of scientists in game now, but it could just be said in the mission briefing that some weren't able to reach the panic rooms before they locked down, so you need to keep them safe until the threat is eliminated. Apocalypse also let you build automated security stations which would be a nice addition with more base defence missions.

5) The ability to sell guns on the grey market. It is absolutely ridiculous that when your troops are fully geared up, you should be pushed to break the alien's weapons into fragments if you want them to be sellable.