Stepping back from individual units and specific days, there are quite a lot of short-forms at the moment and they don't really show up in data that focuses on punctuality and cancellations. It doesn't seem like 3/5 810s and the remaining Cl222s are quite enough to cover the timetable at the moment.
This leads to situations like yesterday when the 1902 Sheffield was only 5 cars. Customers were unable to board due to severe overcrowding, and spilt over onto the 1905 which ended up similarly overcrowded. Looking at RTT, 5 peak time departures from London are planned for 10-car operation today. Only 2 of them were 10 car yesterday. Not good enough, and certainly the main EMR-specific complaint from "normal" customers is about overcrowding (in addition to the national-scale moaning about prices).
i.e. it feels like we are still a few weeks away from getting back to the pre-transition level, when EMR had all 27 Cl222, and a good few months away from the halcyon days when they were augmented by the 180s.