Excellent write-up Doug, appreciate it! I also see it more and more in my promoted ads. I think they're now trying to get users. I haven't tried either; however, I don't like the proprietary F3 format, or do you know if you could also use Parquet, Delta or other formats?
I think you cannot compare it with Dremio as Demio is just a Data Visualisation tool with a lot of in-memory Apache Arrow, so not persisted. I categorised these tools in OLAP-Technologies (Druid, ClickHouse, ...), Cloud Data Warehouses (FireBold, Snowflake, BigQuery, ...), Data Visualisations (Dremio, Informatica Data Virtualisation, ...) and Serviced Cloud & Analytics (Looker, Sisense, ...). In case of interest, here I wrote about the different technologies: https://www.sspaeti.com/blog/olap-whats-coming-next/#list-of-cube-replacements