Sorry to clarify, "best" means most well filled and lesser impact of the passenger decline. Not really a commuter route and with lower covid numbers down here more have continued travelling, many trying to escape the virus!
Since the SW depot sickness, almost all the b and h fasts have had pewsey westbury and castle cary stops added. This adds between ten and 15 minutes to the schedule (largely due to the lower speeds going into westbury). 15 mins may not seem much but if it pushes up a padd to plymouth trip from 3hr10 to 3hr 25 that certainly isn't a good thing.