Season 3 wasn't a bad season, it just seems to have been filled with a lot more average to slightly subpar episodes. The Trilogy of Terror as it was known wasn't so bad to watch the first time. It seems like Voyager hate that let it be named yet the spring 1998 block of DS9 was left unnamed (His Way, Valiant, The Reckoning, Profit and Lace, Time's Orphan) or that stretch that was so dull/crappy in Enterprise Season 2, it drove away part of the audience (the stretch starting with "A Night at Sickbay" and ending before "The Catwalk").
I just watched "Flashback" last night. Tuvok's terrified eyes and the "Don't let me fall Tuvok! NOOOOO!!!!" were quite cheesy. It is better to be cheesy and humorously bad than to be just plain bad. The rest of the episode was decent. I guess with the plotholes, Sulu should have given the order- "Helmsman. Plot a course through that plothole at one quarter impulse".