I had Professor Oberlin for 115A. 115A is kind of the standard first upper division math class that most people take. I would strongly recommended Prof. Oberlin for this class and other upper divisions if possible. I do not know about his teaching in lower div. classes so I can't speak for that.

He presented the material in a straightforward, but organized way. He moved pretty fast and covered a lot in a class but he also had 3 office hours a week so if you had questions, you could go to those. 115A also meets 5 times a week (2 discussions) so there is a lot of help available which is good. One thing I liked about Oberlin was that since the class does emphasize proof writing, he did an intro to proof by contradiction/contrapositive and induction. It was not too thorough but it was pretty good.

His first midterm (I am currently in the class) was really fair. I thought the average would be really high but it turned out to only be 50%. If you are able to do the homework problems and such, you should be good. He does definitely emphasize proofs on his tests, as should be the case in 115A (33A is the more computational side of Linear Algebra). The proofs on the test are doable though. I obviously liked Oberlin since I am taking him again next quarter. He is a good professor- maybe a little less talkative/personal in his OHs than other professor but a cool guy too.