Both resorts are beautiful to be honest. I would maybe choose CSR over CBR thou...simply because the buses are by far the best i've seen. I never ever had to stand, even going back to your resort at park close. Really amazing. Plus, CSR has fewer bus stops at the resort than CBR. I disagree about CSR having a conference feel to it. I stayed there before the reno's were going on and didnt feel this at all.
I'd go with whichever is cheaper and whichever you like best. Both are great choices.
Just back from CSR and we did have some times where we had to stand on the bus, but we were there in busy October. March has the propensity to be busy as well, so I would expect buses to be the same. If you do go with CSR, I would book a preferred room - bus stop 2 outside the preferred buildings is first pick up and first drop off, which helped our odds getting a seat on the bus.
Also, don't let the bus stop situation at CBR deter you - they fairly recently changed it so that not every bus services every bus stop. Buses don't cycle through all 7 stops anymore, which is a big improvement there.
I wouldn't say CSR has a conference feel to it, but conference attendees are definitely abound. This was our second stay there and have always noticed their presence. It's not problematic, but does pop the vacation bubble to some - as someone who attends conferences for my own work, seeing the laptops and lanyards just reminded me of work! Not an issue though, just is what it is. The conference attendees also made Laguna Bar and Rix Bar very crowded, along with the Disney Springs buses after 6pm or so.
All of this said, we'd still opt for CSR over CBR. Even with the construction, its a beautiful resort and we love the atmosphere. CBR wasn't our speed last time we stayed there, but the newly remodeled layout is appealing and making us want to give it another try. Both resorts are centrally located, so I wouldn't worry about commute times.