Buses seemed to do pretty well (in the Bus & BRT thread we discussed that they were moving too fast in the empty AM streets, resulting in bunching at terminals)
Commuter Rail, when I looked at about 6pm at
https://mbtatrains.com/ (my new fave) looked like:
NEC and Worcester were all on time
Fitchburg had serious problems with bunching (three outbounds delayed moving together)
Other lines had moderate delays
Personally, I rode my 37min 80 bus in 23mins inbound West Medford to Lechmere, and went home at midday GL->Lowell (to West Medford) which was, at 12:15 super punctual and still only filling one double decker behind the locomotive.
I spoke to the driver of my express bus (the 326 West Medford-Haymarket) this morning and the driver reported that at the worst of the storm, buses moved OK because the streets were empty of traffic.
The bus driver this morning said that all his regulars who commute to office jobs at MGH had been told to telecommute yesterday.