I like the ease of building forms and convenience of integrations.
There was a specific update to credit card fields to make them PCI compliant. I don't think that formstack understands how their customers are using the fields because when they replaced the fields (to be PCI compliant), they don't realize that their customers are just collecting credit card information and started forcing them to process payment at time of form submit. Their update did not say anything about this and when asked for extension of time to change processes (they gave 30 day notice), they said that would not happen.
They are a great tool, just really unaware of how their customers could potentially be using it and don't mind breaking their business processes at short notice.
UPDATE: Formstack did extend an extension to this feature rollout (CC). I am now able to properly plan a billing process around this change. I am changing my review from 2/10 to 9/10 stars. I do like the ease of the forms. Thank you!
Do not use this tool to build into your regular business processes. It will likely change and require development work to rebuild your processes after the change and the company sticks to their deadlines.
billing information collection
customer satisfaction surveys
internal ticket submissions