While they have some memorable and endearing front line employees, the operation as a whole seems hit and miss. We booked a 2 day plus night tour package with them through Celebrity Cruise Line. Our 2 days in Frisco were the long anticipated highlight of the entire Pacific Coastal cruise. Thank goodness we had this generous stay-over as day 1 was a near wipe out thanks to GreyLine. That day a wacky but very peaceful marathon/costume walk snaked through the city. It necessitated some temporary street closures and day long hop on-off location adjustments. Fair enough. An annual event, known long in advance, the company however choose to leave it's hop offers lost and stranded. It's drivers and narrators did their best but could orally forewarn only so much on the fly and still keep the tour and banter on the road. All that was needed to back up the front line staff was a little staple on hand-out detailing the day's route changes and perhaps a phone number where a live human could be reached. No such luck. We two seniors ended up walking all the way from Golden Gate Park stop 11 to stop 17 by the Hilton downtown. There we were finally able to find a functional stop to hop back on, and even then we had to guess. The high wind chilly day was consumed by searching, waiting hours at designated stops that didn't pan out and walking miles to find another. We triggered a roaming charge to phone for help. After navigating the cheery-frustrating "push this for that, that for this", finally got the (ever cheery) "No one is available take your call". On we trudged, including right through the Tenderloin area. While I appreciate the area has come a long way, zig-zagging over and around folk we seemed the only ones not challenged by abject poverty and devastating addictions. However we were only robbed by GreyLine! Other's on our ship expressed their own woes and disappointments with this operator. The most astonishing were the excited ladies from New Jersey loudly recounting that on a hill, just mid way into their tour, their coach ran right out of fuel!! How in blazes can that possibly be? We ourselves witnessed two cases of mechanical issues, one involving the bus having to be evacuated to await the next, leaving some unable to get seats. San Fransisco is the perfect setting with an endless supply of tourists. How can an Operator of such a service go wrong there? It seems Greyline finds a way. Until you read about a management make-over, I'd choose another hopper in San Fransisco.