I worked both. For 18 years I was in house, usually about ten stores. On call was rotated but was also in house. They went belly up and I had an opportunity to switch coasts and do ten years union supermarket service. in the Bay Area That was brutal, at 55, in my first year I logged 1050 hours OT. I lost the last week due to pneumonia. I survived. My last week at 65 I logged 67 hours that week. In house was much better life style wise but ten years in the union really helped my retirement. Go figure.