Qlik Sense

Qlik Sense is a self-service analytical tool based on the same in-memory technology as QlikView. It's associative engine allows for snappy selections, filtering and prompt re-calculation of all charts and aggregations on the fly as the user navigates throughout the dashboard, even on datasets of over 100 million rows.
Qlik Sense focuses more on the self-service aspects of BI, where users are encouraged to build their own Adhoc visualisations without the use of keyboards simply by drag & dropping various elements, making the technology utmost business friendly. Also, as the whole technology is fully web-based, it embeds the latest visualisation libraries (D3, Raphael etc.) and allows for a seamless integration of customised extended JS charts (so-called extensions). The latter enables for unlimited possibilities when it comes to visualisations (http://d3js.org/) and further integration with web-services (R servers, real-time analytics, Hadoop etc.). Also, the Qlik Sense Server deployment is tailored to facilitate a multi-node deployment, allowing for a very scalable enterprise solution, even cloud-based.
The data security technology (Section Access) is the same one as in QlikView and is customisable, secure and robust.

All in all, when it comes to deploying a scalable and business-friendly BI solution, which has very presentable dashboards, a fast and robust aggregation engine with extended self-service capabilities, Qlik Sense is currently the best product of its kind on the market.

Qlik Sense is still a new product and not very mature yet, as it has only been released a year and a half ago. The review is based on Qlik Sens version 2.1 which is important to emphasise, because QlikTech is constantly updating the software and publishing releases with enhancements and bugfixes.
Qlik Sense is not the right tool, if you requirement is:
1. To have a guided analytics dashboard, where the user is constraint in the way he views his data.
-> This can be overcome by creating mashup websites, however you will need a web developer to do this.
2. Standardised reporting via Qlik Sense and production of pdf files is not possible (yet).
-> An integration with nPrinting, QlikTech's latest acquisition, could change this and it's on Qlik's roadmap for the next year.
3. Your BI solution needs to accommodate flexible data extraction capabilities (e.g. to Excel).

General current disadvantages:
1. The story telling functionality is not mature yet - users have more benefit using PowerPoint directly. In my opinion it's missing a live connection of the snapshots used in the story to the underlying chart objects.
2. Security settings (NOT on data level) are governed centrally via the management console and are complicated to comprehend.
3. No guided analytics aspects, even navigation between sheets can't be controlled.
4. No supported data extraction capabilities. It's almost impossible to get comprehensive extract of it's underlying data, something that was possible with QlikView (Export functionality e.g.)
5. The vendor has little practical knowledge on how Qlik Sense is deployed enterprise wide within a business and is not really able to support.
6. The vendor is focusing more on the data story telling and collaboration aspects of the Qlik technologies and almost imposes those on the business. Personally, I would prefer if QlikTech listened to its customers a little bit more.