I have both, total tech and AC+. I bought MacBook 16" and Studio display with 3 year AC+ from Apple Store but I bought Beats fit pro, AirPods and other stuff under total tech at BB. If you only buy one Mac than get AC+ but if you will keep buying electronics get Total Tech. Total tech gives you automatic AC+ for apple stuff. If its a 3 year AC+ possibility, BB told me you can buy TT for 3 years and keep it under warranty with AC+.
Total tech is also good for other things like if you need to mount a TV on wall, install security cameras, install dishwasher, BB will come and do it for you at no charge with TT. Also they will deliver same day to your home but its a nice option if you have a family or buy electronics regularly.
the only reason I bought the Mac stuff AC+ is because I dont know if ill keep TT for 3 years. I'll keep it for 2 years for sure. 60 day returns are also nice although I don't like doing that.