After 3 full campaigns, numerous restarts, totaling 200+ hours of XCOM2 I recently returned to LW. I've installed a bunch of PatcherGUI mods, increased the squad-size, and maxed out the difficulty and I have to say that everything pointed out in this thread is 100% correct. It is ball-busting but balanced, and incredibly fun to play LW. Full stop. I do not have the same feeling towards XCOM2.
I think that there is one important aspect of LW that hasn't been touched on, and that is atmosphere. I've said before that XCOM2 feels like a "Military Operations Simulator" simulator, it is very light on atmosphere and relies very heavily on extremely linear tactical and strategic decisions. Clearly, comparing XCOM2 to LW is not quite "fair" because the comparison should be with EU/EW from a purely platform standpoint, but given the comments and platitudes coming from Firaxis one could imagine that they would WELCOME the comparisons to LW.
Each mission in LW (especially the first time around) was challenging and deadly, but was almost always a puzzle to be solved; whether Exalt, or a landed large, or a terror mission, or council mission there were different strategies that worked for each different scenario that might not work on other missions. I use essentially the same strategy for every mission. In XCOM2, the timers on some missions just seem to force a singular strategy on the players, and the dark event alerts that force the player to stop what they are doing in the strategy game to immediately deal with a tactical mission, really ruins the atmosphere of the strategic game (if I am the "Rebellion" why am I not forcing the the Advent to react to ME and not the other way around).
For my most recent Legend play through I used these mods and it was the best experience yet, but until the proper balance of Avatar timer, fatigue, and mission control is achieved I will probably play through a LW Impossible campaign and wait a bit to play XCOM2 again:
A Better Advent
Additional Dark Events
EU Aim Rolls
Extended Dark Events
Field Medic
Grenades Damage Falloff
Improved AI
Improved Zombies
Increased Enemy Squad Size
Landed UFOs from day 1
Lucubrations Infantry Class
Lucubrations Sniper Class
Maps by Vozati
More Maps Pack
More Starting Soldiers
Rogue Class
Scanning Sites Plus
Soldier Fatigue
Start Your Own Missions
Trooper Class
World Expansion Project: ADVENT