We don't mind them too much, though they are pretty rare these days in our business (customers are already lean and don't have time to send people all over creation to do audits, so they use "self-assessments"). Most of the time, they are usually visits with a request for a copy of the ISO reg. I've been through several full QMS audits though, and while time consuming, it was no worse than a surveillance audit.
We LIKE to see the customers come in, even for a full blown QMS audit, because we've had to separate ourselves from the rest of the world-wide industry by staying away from most of the commodity stuff and concentrating on specialty products, quality, and service. We feel that if the customer would come only in and check us out for themselves, we would have a better chance of getting/holding the business, even at a higher price.
If we ran into a customer that tried to put unreasonable demands on us with an audit (do CA's contrary to our own procedures, audit to a different standard, etc), we'd have to look at the demands made versus our contractual obligations with the customer (i.e. where the customer's procedures for suppliers are spelled out in the contract/PO). If there was nothing in our contract that made us agree to follow the customer's wishes here, the Boss would have to weigh the cost of losing the business vs. telling them "No thanks" on following their wishes. Several years ago, VW came in and did a QMS audit. We were ISO 9002:1994 and they were going to audit to TS. We told them up front that they could audit us to TS, but any NC's not under 9002 would not necessarily be addressed. They were fine with that, and the audit went well.
All that being said, if I had a customer in here every week, it would get to be a real pain in the

!
