Now I've been a massive fan of Tom and Jerry since I was a kid and this love is one of my best memories with these characters. After rewatching it, I still find myself enjoying this movie as an adult.
Positives for Tom and Jerry & The Wizard of Oz (2011):
There is some fun to be had seeing these characters and their shenanigans taking place within the 1939 movie. The animation is always constantly great in these Tom and Jerry movies. And finally, you still get the classic running gags that these characters are known for and how they constantly survive them over and over again.
Negatives for Tom and Jerry & The Wizard of Oz (2011):
It is literally the same movie as it was back in 1939 only with Tom and Jerry thrown into the mix. The little gray mouse following Tom and Jerry on this journey was unbearably annoying. I also really annoyed with how dead ass serious Droopy Dog was with his job trying to guard the Wicked Witch of the West.
Overall, if you want to see Tom and Jerry in The Wizard of Oz (1939), then this is the movie for you. As for me, I had a decent time with the premise.