We are using admin labs to monitor our website performance, it's easy of use with good customer support from their team as well! It has helped us improve overall web page load time by reducing unnecessary resources that were loading during visits (css/js).
There is nothing I dislike about this service so far but if you want best features available in market then go ahead otherwise there can be something missing which may irritate users like me who have used other products before moving over here :) The most important thing i liked was its ease-of -use nature while working remotely without any help required at my end apart form few tweaks made locally when needed only!!