Seriously if you're worried about time for the tournament then you're doing it wrong.
1750 and 1850 bring nothing but a 1500 point list with something ad hoc tacked on to fill out the army list.
Now I'm a IG player and have three different list I run, my Air Cav, my Ryza Regiment and my actually competitive list (which I rarely bring out since I like a challenge and shooting a army off the table gets old quick).
My whole area everyone plays at 2000 point list and all the tournaments are 2000 (central-south eastern NC), yet I go almost anywhere else and it's almost always 1850 pt tournaments. I hear the same two arguments over and over. Time limits and 'player skill'. I call BS on both. If you're worried about time as an organizer then you're doing it wrong and not properly planning out the times. If you're claiming skill that's a red herring. Why not run 500 or 1500 pt tournaments instead? Skill will always shine through in the end.
That being said I can complete at 200pt Kill team list through 2500 with no issues (thank god the IG codex skills very well). But I've found that at 2000 pts good army lists really fill out and bring the best of the newest codices to the table. All 5th Edition Codices are built with 2000 points armies in mind.
So why this sudden uptick in 1850 pt tournaments in the last six months?