The best feature of this product is called "remote interpreter", which allows to run and debug python application on remote servers via SSH. This feature combined with vagrant support allows to maintain a lot of development environment without much effort and these environments are really close to production configuration.
Smart autocompletion works really good. Code inspections is a really helpful feature, which allows find bugs on early stage of development.
Hot feature in latest versions is Docker support.
It has a feature for switching colours for colourblind people.
It has a lot of plugins for database support, issue tracking systems and so on, so you could not leave IDE during your daily work.
It supports all major OS, so it allows all developers establish a similar workflow
Inspection and autocompletion sometimes don't work well with modules which have a lot of dynamic code generation/importing.
PyCharm requires a lot of memory and a good processor.
Remote interpreter and support of web frameworks available only in professional edition, which is not free.
Minor glitches and bugs might be really annoying.
I'm a software engineer and PyCharm is crucial tool for me. It helps me to write a reliable code and work with multiple project at same time.
JetBrains has a good support.
Price is sane.