I travelled from Darlington to Manchester on the 13:35 on Tuesday returning on the ,13:00 on Tuesday. In both cases the dedicated serving staff were very friendly but, although the food I received was good (probably better than LNER) my overall impression was food shortages and slightly chaotic.
On both trips I wanted the burger but on the outward trip the only hot option was the pie and mushy peas, which was very tasty. I was offered drinks at least three times and snacks once - I didn't get the opportunity to get a piece of cake after that. People boarding at York were told that there were no meals left.
On my return the only hot options left were some breakfast items. I had an omelette sandwich which was surprisingly tasty. The host actually forgot to serve me after taking my order and then, after I asked about my ordered food, forgot to serve me and the table opposite drinks. I wasn't offered snacks or cakes on this trip though the people immediately in front of me were.
In both cases the carriage was only half full which suggests that if the service was busy there would a good chance that you wouldn't receive food. It's a shame as the food is good and the burger looked very tasty for those who managed to get one.
As an aside later in the day I took the TfW service from Piccadilly to Shrewsbury and availed myself of the restaurant on that. Food and service were absolutely spot on.