I liked the unique dome shape and artistic touch of Grav's Upline pipes. I regret nothing!!!! The "rings" rule; they are aesthetically pleasing and create a cool cone-shape of bubbles when in use. It also makes a deeper "glug-glug" sound you might only hear from larger pieces ;-)
I'm big on keeping a clean piece, and after a month of daily use, I've had no problem keeping it looking clean and fresh.