<p>Strangecharm: I only know one person who enjoyed 23, and 7-10 who really did not. 23 seems to be a lot of memorization, rather than actual conceptual understanding of mathematical proofs. Most of my friends who’ve taken it also say that they got very little out of the course other than the ability to say they’d taken it.
You might try filling in some MV/lin alg gaps yourself over the summer like you mentioned and/or looking at some of the course material (homework, exams, etc) from 21a and b. If it looks like you’ve got a good grasp of the material, you might even want to consider something like 25, which my anecdotal evidence suggests is much more rewarding than 23.</p>