We love how simple it makes our daily tasks of creating leads from different sources very fast so we can focus more time in other aspects like sales or management which are important too but not as much fun! Nothing specifically at this moment because everything looks great when you first sign up with them!! I would say that they do have some bugs though sometimes their servers go down causing us problems during peak hours (12AM-5PM) however once fixed again there's no issue afterwords until next day happens..
And yes i'm aware about "the problem" where your data get deleted randomly by accidently pressing wrong keys while working through dashboard etc.