I experience assigned seating this weekend too. I don't know if I like it. On one hand, you can get your ticket and not worry about missing a good seat while getting popcorn. On the other, it takes people forever to pick a freakin seat.
When I used to work at a cinema in England assigned seating was the norm for any showing that was expected to be busy, I actually prefer it because it gives you the opportunity to select a seat before you go to avoid disappointment.
When we went to see The Force Awakens at Showbiz in the SDX auditorium it was unassigned and we left because we ended up right at the front, we complained to Showbiz who said they were working on it (which apparently they have) and gave us free tickets to go again but the only one at the time with guaranteed assigned seating was all the way in Baytown, but we did make the trip.
They have since opened the one at Fall Creek which is also assigned seating and so the last few big movies we have seen have been there. Alamo Drafthouse which is our pick for smaller films also switched to fully assigned last year.
As mentioned, generally it is better, although I suppose if you only ever buy at the box office it could be a pain. But I will say this, for a quiet showing after the lights go down you would be perfectly free to move seats if you aren't happy where you are.
It does seem to me that if the 80's software that my former UK employer was using was able to switch from assigned to unassigned depending on need then the fact that these chains don't have that ability now is a little pathetic.
I would also add that ShowBiz are particular bad at getting through lines, it seems the entire staff is what we would call "half-soaked" and has no sense of urgency, that was the cause of another complaint to management. I am 16 years older, much heavier and much less fit than when I did their job but I could still run rings around any of them!!
We went to the movies to see Tarzan while in Cali. (Cool movie!) You had to buy tickets online to reserve your seat and it was assigned seating. It seemed to work out except for those who couldn't find their seats and wandered up and down the aisles after the movie started. But the prices! $12/seat. I'd pay it again! They were awesome,wide, leather recliners!