Is it just me or does free food and booze always seem to taste better?
No.
I can tell you that back stage catering can be a lovely eating experience or can induce artificially fond memories of your sister's (or your own) first home economics meal. If you're working on a show where the crew is fed with along with touring production, look for Dega. You'll be eating well.
We had a casino gig that included meals at their buffet restaurant and we ate there enough that we could tell if Chef had been through recently or the line staff was running the kitchen.