We're a rather large shipt volume store. I have a handful of regular shoppers that I have built decent relationships with, just like my regular guests. Almost all of them are super nice but there is a couple that can get snippy if you're not fast enough or don't have what they're looking for (which is rare and I'm typically able to offer a substitute that satisfies their client). I do have one shopper that has figured out how to clear the phones after they trigger a fast service request. They'll occasionally get mad when no one shows up because everyone thought someone else had cleared it xD
On the whole, I really like the whole program and it helps us capture guests that wouldn't normally come to the store; being the only location in town that doesn't have Curve Side, it's really important to me to keep the shipt shoppers happy so their clients are happy as well. I'm not sure how it's functioning in other groups but here, Target is the second retailer to support shipt, behind a large regional supermarket so I feel like being competitive and keeping those shop goals 100% is really important.