First of all, this is NOT a brewery. It is a museum inside the old Guinness brewery. It has elaborate (but very basic) explanations and demonstrations of the process of making beer, but anyone who's been to an actual functioning brewery or knows about beer would not be learning anything here. It's also ridiculously reverent of Arthur Guinness. I'm surprised they didn't have him embalmed and make you line up to see his corpse like Lenin in Moscow. Anyway, it's a somewhat fun place, and the views from the Gravity Bar are not bad. Also, don't expect your Guinness to taste vastly different here. That's a myth. The differences, if there are any, are subtle.
Thank you for visiting the Home of Guinness. Sláinte!