The interface is very easy to use, I've been able to find my way around it in just minutes!The only thing that could be improved would be if you can have more than one person involved at once (even though this isn't really an issue for me).
It's free and has no limits or restrictions so try out all of their features before making any decisions about your needs/requirements. We are solving our scheduling problems by using appointments instead of meeting rooms which makes communication much easier between employees as well as being less stressful when arranging things such as presentations etc.