What do you like best?
* Seems a bit faster (after the initial load/cache)
* Mobile support is nice
* CVS export data also helpful
What do you dislike?
* Kibana 4 interface is more complicated than 3.
* Small things like finding out how to generate short urls is hard to find
* Re-creating saved dashboards in 4 wasn't a 1:1 parity transfer.
* Sometimes it's hard to find what you're looking for because the incoming logs are bleak. The flow is all over the place.
* The scrolling fixed position CSS they do is also quite annoying.
Recommendations to others considering the product
It's very overwhelming at first. I recommend learning all types of queries (field base queries, regex queries, range queries, boolean, etc).
What business problems are you solving with the product? What benefits have you realized?
Log monitoring. => Funneling for debugging.
Visualize data. => Dashboards for everything.