Thanks for the replies everyone! The responses are sort of a mixed bag, but at least I can simplify it down to the question of whether I think a 38 min connection in MSP is worse than a 45 min connection in ATL, or vice-versa -- good idea to take SLC out of the equation.

Headed to PSP. The problem is that there are only two flights from SLC that day, so if I miss the first I'm stuck for 8 hours in SLC waiting for the next one. The options from either ATL or MSP after a misconnect wouldn't matter so much -- I'd be screwed either way.