Hi,
I'm (or was) a qlikview developer but have been working with Looker the last year.
I think you need to realize that Looker works differently. Looker does not store any data. It's like an SQL editor with visualization where you may model your data and distribute the model between different dashboards, objects etc. All of these reachable through an API so you can let external/internal apps connect through rest-api to fetch data that you already modelled. The models are converted to SQL when you run a dashboard, graph, query...This "semantic layer" is created with "Look ML" that is very simple to use.
If you want, Looker may also cache the results of each query you run to display results faster next time. The models created can be extended, imported and/or browsed by users and developers in other projects. Users can drag/drop dimensions and measures and create their own calculations. All of these are translated to sql by looker using the models created.
My comments below.
Three things I found best in Qlik Sense than Looker:
1. Better way of connecting to data sources in Qlik than looker. Looker is based on API connectivity mostly or its very complex to connect looker to like MSQL, needs SSL SSH tunnel which are complex.
1.1 Looker connects to a lot of different databases such as MSSQL, BigQuery, etc Havent needed to use ssl or SSH yet but then I have only worked with cloud based solutions like azure dw, snowflake, bigquery.
2. Qlik ETL is powerful and can solve complex use cases especially create missing data which is not available like master calendar creates such date records which are not present in data.
Looker has ETL but not so much powerful and no capability to view data model architecture.
2.1 Anything you can do in SQL, you can do in Looker and even more. You may also let Looker schedule and run your queries and save the result back to the source database which lets you create some form of transformation. Looker lets the source database do the heavy lifting. Calendars can be created in SQL so no problems there. And yes, you may see the model architecture but not in a nice "star schema" as in Qlik. Looker scaffolds the code it needs to help you out too.
3. Variety of charts, 3rd party extension comes in Qlik but I am not sure looker has also 3rd party extension cap
3.1 Looker have 3rd party extensions and "blocks" which are like dashboards, models, connections all together.
4. looker is cloud based, not sure how it deals with load balancing.
4.1 Looker is cloud based on AWS or GCP. On-premise version is available as well. Load balancing? this is taken care of by Looker on the platform you use. No need to worry about the infrastructure, its "under the hood" at least on the standard cloud version.
5. Looker is good with API data sources.
5.1 Yes and Lookers rest-api is nice to use.
6. Not much tutorial content is available for free on internet
6.1 Their website have a lot of information and I think you must register (free) to access all tutorials.
Any way, I think there's no "best" tool to do it all. If you compare feature by feature Qlik will be better I think but Qlik have like 20 years of "lead" right? It all depends on what the customer needs to do with the BI-tool. What infrastructure they have, if they're using cloud DW or not. Looker is doing great stuff and growing fast so there's more to come!
