I disagree. I think the acting is impressive in comparison to the recent seasons. While it may not be as good as the acting in MMPR, Time Force and SPD, it's certainly not the cheesy acting that you see in Operation Overdrive and Jungle Fury. So I would say it's acting is on average for a Power Rangers season.
I thought the acting in Jungle Fury was ok though (Nobody seems to like that season for some reason but I liked what little I saw of it since I kinda stopped watching after Mystic Force) But as far as acting goes, I think this current season is the worst. And that's saying something when you think about the over-the-top cheesyness of 90's kid shows. This season's acting makes Beetleborgs' and Ninja Turtles look like freakin Emmy-award winning blockbusters. And dooooon't get me started on the villains we've seen so far! The rangers' acting is more...stale than cheesy but I REALLY can't take the villains! Especially the one who could kill people with insults that were about as hurtful and clever as a "Yo momma" joke