I think profs are preferable but admissions knows that sometimes TAs are who you interact with on a daily basis and who actually know your work. So it wouldn't be a bad thing especially if it's a glowing letter of recommendation.
I did some Googling and it looks like this test was the same as the international LSAT on December 3rd, 2016 (https://forum.powerscore.com/lsat/viewtopic.php?t=13006). What do you all think?