I stayed in Shimla 2-3 months back and it was one of the most pleasant experience. You may definitely call the helper boy lousy or slow but other than that everything was upto the mark.
Green retreats also seems a good option but since the OP wanted a peaceful location, that you may not find in a crowdy place like green or others. Book the guesthouse completely and spend your time with your loved ones with peace, take a walk in the night buy some general items like milk etc that's also worth it.
I also thought going with a GDP operated guesthouse I will regret but I didn't may be it was a bad day for you.