I like how easy it was for us as an agency team, when we needed help with something new or better features! It's very flexible so there were no limitations set by our side which made things easier than expected - also they helped me out during some issues i had while migrating from another provider (which ended up being too expensive). Their support isn't always perfect but overall their product works great without any problems at all reported yet :) We're using replay primarily because of its flexibility & ease-of use compared w/ other providers such has MailChimp etc where you have more limited options if looking just around certain aspects within those services e g., tracking emails opened vs unopened / unsubscribed users and reporting them accordingly.