I have been going to Cafe Mysore for over a year now. Here is my unbiased view of the place.
The food tastes great. All those who are looking for authentic Kannada food, don't look any where else. For me, the south Indian thali they provide during lunch is the best. I like this place because the food they cook here tastes exactly like it does in Bangalore/ Mysore. I know because I was born and bought up in Bangalore and have spent over 20 years there before moving to Mumbai. The taste of the food brings back fond memories.
The downside is that the service is at best average. The guy who greets you at the entrance to put you in a queue basically yells at you. One time, I asked if there was a table in the AC section, he just blurted "No, no AC"!!. Judging by his reaction, I thought the AC section was closed. Later I saw people sitting inside the AC, so when I prompted him again, he said its full and it will take 25 to 30 mins (still yelling). Ironically, we got the table in the next 2 mins.
He was basically discouraging people from going to the AC section so that he could reduce the queue. For a hotel with this legacy, to be lacking in basic customer etiquette, was highly disappointing to say the least.
They are also terribly understaffed, and the waiters again lack basic etiquette. They even grimace when you ask for an extra item post billing.
So you never really feel welcomed there and you would be lucky if you had a good experience at the hotel. I have now slowly started avoiding the place by substituting it with the next door Madras Cafe who are far more customer friendly, despite the large crowds.
But I still recommend you try the place once and I hope your service experience betters mine.