We've done both before (on our own with rental car) but are going with newbies in February and they'd like to do this tour. I'm fine with doing it again as it's daytime and doesn't interfere with my show schedule. I'd prefer not to rent a car this time - rental rates are more than twice what I usually pay and I don't want to deal with driving / parking / schlepping (and I won't pay to park!). SO...it looks like this is only available through Grayline. I've read a lot of good reviews, but a scary number of bad ones. Any feedback to share on this option? IF we are to book it with Grayline, I found one 10% off code (VISA) but wonder if anyone can suggest a better discount. Thanks!