For what it's worth: I've met 4 different pharmacists that started at CVS/Walgreens/Rite-Aid, etc. and jumped ship to work at a grocery store pharmacy. ALL 4 of them are happier, less stressed, and have ZERO regrets about making the move.
Kroger, I've worked at CVS and I guess it depends on where you're located, but the one I worked at filled about 3,000 scripts a week so stress levels were pretty high especially with the drive-thru. I'd choose Kroger any day.
Kroger all the way!
I have never met a CVS pharmacist that liked their job. I've worked for Kroger for ~4 years. You would be hard pressed to find a better place to work as an intern as far as community pharmacy goes. We have many pharmacists that now work for Kroger who used to work for CVS and they are much much happier.