Same here - we have mass vax locations spread around the valley. It was a 6 minute drive and I parked right in front and was in and out in 20 min including the 15 min waiting time afterwards. It couldn't have been any faster at a pharmacy, I don't think.I agree that the more local approach is generally preferred. I did generally find the Mass vax sites to be very quick and efficient though, didn’t take any longer at the Natick Mall and Foxboro Stadium sites than my dad at CVS. It would of course depend on how far away you live from one for the commute time, but the actual time at the sites was 20-30 mins tops (based on how long of an observation period you had). They were run really well from everyone I spoke to and my own experience, you got there 10 minutes before your appointment and you went right in. Sites were also open past workday hours in most cases and on weekends. In some areas the state was also providing rides for those who didn't have transportation.
And there is decent public transit to those locations too.