To migrate content or DAM, we started with vault, but performance was not very good (1Gb/ 1h aprox). So, we try to use crx2oak and time was better, 1 Gb / 1 sg aprox, but new instance does not work, we have a lot of inconsistences. We have thrown a consistence check and a lot of records were missing.
Which is better to migrate content crx2oak or vault? Could be the problem previous copy from vault because were previous data or references?
Vault would be slow as it does a http hanshake for every node and thus any network latency impacts performance. crx2oak is preferable when migrating data from older CQ versions based on Apache Jackrabbit 2 to Oak. Though it can also be used to copy data between Oak repositories, prefer to use it when content leverages any features only found in Jackrabbit 2.
For transferring large content, Grabbit would work better. Grabbit provides a fast and reliable way of copying content from one instance to another. It creates a continuous stream of data and thus avoid latency issues & providing speed improvements up to 2-10 times.
Additionally to your last point, whichever method you use, try to transfer the content on a fresh copy (previous tool usage might leave some issues/ inconsistencies).