Another big YES vote from someone who's parents went away without the kids and who has gone without my son.
I have the greatest memories of my grandparents coming to visit and staying with us while my parents would take a vacation. My parents did this about every other year or so. It was sort of a vacation for us as well.
Since her parents let her get away from us for a while (and with 4 of us she needed it!!), my mother now believes that we each need breaks as well. She has a standing agreement that she will babysit for one vacation a year and a few weekend/overnights if we want. We have not taken her up on it each year but did go to Hawaii for 12 days when my son was 1, did vegas for 5 days when he was 3 and have a done a few one night things. He is now 4 and this year we are going away without him in May (maybe to Aruba as well). My son loves grandmom and grandpop. Just a few minutes ago I told him that we were going to grandmom and grandpop's today for dinner. "are the babysitting me" he asked. I said "no, we are staying". He said, but grandmom hasn't babysat me in a long long time, when do I get a turn!!