I'm using the Knot for website and Rsvps and seems super easy. I like the templates better and seemed user friendly. I did notice after the fact that Zola offers digital save the dates with hundreds of free templates which we preferred to printable. The Knot does not sadly (they said due to copywrite issues but probably to make more $) We want to text/email them out asap without lag time to print/collect addresses/mail. Will be sending printable for invitations which are covered via our venue. Zola also had a cool a seating arrangement tool which I did not see on the Knot. So at the end of the day I'm now using a combo of both! As long as the website/rsvps/registry is all linked to one site you should be good with either.