I like that we have been able to use their services without having an agency or broker involved so it's all one team effort! The only thing i dislike about them would be if they didn't offer as much flexibility with our account setup process but this has improved over time too now when booking through us clients are always happy at how simple everything was from creating accounts etc.
We've started using wl solutions because previously doing things ourselves meant not being 100% sure what exactly happened each step along way during any journey which could lead to confusion down line - WL solves these issues.