I've been taught RADALT in the fleet. That being said, reread A4s post about your instrument scan. If you can build your scan around the boat to have the radalt (which is what I certainly do) then stick with that. I've gotta say though that a lot of how I fly is based purely on the sight picture. I cross-check how it looks to my altimeters (both) and see if it jives. And when setting the baro, I'll set it to whatever Marshall tells me. However I'd say that the error can be a lot more than 75' (especially at the boat). The reasoning for keeping my baro set correctly is because that's what the other traffic are having theirs set at. You wouldn't want to be off from everyone else, especially considering the Case I departure is 500' whereas the Case I pattern is 600' (with the 800' break).