When comparing these two products the main differences that stand out are features and cost. To get in Pipedrive Platinum what you get in Close, you have to integrate with 4 third party apps and pay individual costs associated with them. Additionally, there are some features like automatic historical import of your emails, auto-logging of conversations & automatic call forwarding that are just NOT possible in Pipedrive (with or without third party apps).
There is also a higher cost associated with Pipedrive. For the complete solution, Pipedrive costs $4766 with necessary third party apps, while Close costs $1359.