Terrible IMHO as no restaurant does a Sunday roast as good as my wife so it is with very heavy heart that I buy one out due to kick off or other unusual circumstances
If you avoid the carvery etc then I reckon you could find a really good Sunday Roast BG.
E.g. My stepmum lives round the corner from The Lion and Lobster and every time we've been there when visiting it's been superb. They even do proper Yorkshire puddings (and we live in Yorkshire).
I'm actually starving now thinking about it.....