No douts, this plugin is very easy to use. It will take only few minutes to set up.
But some more functionality must be added as required.
Validation of nubers, date etc
validation of a separate text field without special chacters and more...
Although there are some plugins to add some more validation like number , date etc but by using them the way of validation errors looks very weird.
So, some fields should be added in the contact form7 plugin..