Awesome service! (June 2020)
I found Litextension through the Magento Marketplace. We had an extreme challenge of getting Magento 1.42 migrated to a new Magento 2.3.3 server. In addition we had many custom customer attributes and our sales order flat table had additional customized fields.
I tried out the demo and it was amazing! I didn't even have a Magento 2.3.3 site running and the demo will create a server for you and load it with 20 sample customer, product, and order data. It's unbelievable how well this works.
After engaging Litextension, they were able to map all our custom fields. We've done two full loads and incrementals without an issue.
I highly recommend the service. It's probably the best bang for your buck if you need to migrate data to Magento2x.
Our site goes live in a week or two from this posting. There would have been no way we could have done the data migration without this service.
Response from LitExtension:
16 June 2020 at 19:00
It is great pleasure for us that you've visited our service and purchased our product. We appreciate your trust you put in us and words aren't enough to describe how grateful we are. Thank you for believing in us.
Hit us up if you need anything ;)