I am very interested in hearing about your experiences migrating to vespa. When it was opensourced we all thought it would be an absolute game-changer, but I see so few people building new products (or migrating existing products to) vespa.
For me Vespa is a absolute game-change, in features and as someone said here, ES looks like it intentionally complicated to maintain. With nodes randomly getting unhealthy. Vespa is like Redis to me. I completely forgot about maintaining it and works great.
It makes a world of difference in our product, and I take every opportunity to evangelize it.
This may be of interest to you: https://sematext.com/opensee/report/project/trend?q=ElasticS...
Would you happen to know how Vespa compares to ES in terms of memory or CPU footprint? Have you done apples to apples comparison by any chance?