I highly recommend OTS. I like TMNT (2014), but the sequel is a huge improvement and a step in the right direction. Too bad their won't be a third. Box office was average, but Paramount blew it in marketing. The DVD/Blu-Ray sales were insanely better and recouped the losses, but with the exec's go big or go home attitude, their won' be another one in that continuity. This film has the best version of Bebop and Rocksteady too.Haven't seen the second movie, but I didn't hate the first Michael Bay movie (Even though he was Producer)
BTW: When you get the Blu Ray version, check the deleted scenes. One of them has a special surprise that I wish made it in to the theatrical cut.