I have been evaluating the two for few days now, and came up with a few differentiating factors.
I have played around more with QlikView as they have a free version of QlikView desktop, i like the programmability of QlikView, but it is also hard to beat the easy manner in which Tableau allows to create charts using drag and drop.
This is a sum of my experience with the tool, scouring forums, and internet wisdom.
|Implementation Speed||Good||Fast||With QlikView you need to normalize schema when you load table data. But with tableau you can load data from a table, view or a stored proc and give join conditions later|
|Scalability||Limited by RAM||Disk to L1 Cache||Big drawback for Qlikview and plus for Tableau.|
|Clients for End Users||Browsers,Desktop, Mobile||Browser,Desktop||Qlikview has free Personal Edition Vs Tableau has free Tableau Reader.|
|Interactive Visualization||Excellent||Very Good||Most users value Visualization over Modeling|
|Data Integration||Good||Very Good||Tableau has lot more datasources.|
|Visual Drill-Down||Very Good||Good||Qlikview is fastest thanks to in-memory database|
|Dashboard Support||Very Good||Good||Qlikview is best for Dashboards|
|Modeling and Analytics||Weak||Excellent OLAP||Tableau can also connect to Oracle Essbase and Microsoft Analysis Services.|
|UI & set of Visual Controls||Very Good||Good|
|Technical Effort||High||Low||Tableau requires lot less technical know how to start visualizing.|
|Development Environment||Scripting, Wizard based.||Drag and Drop based.||Filtering and Excel integration of Qlikview is very strong.|
|Datasources Capability||Good||Very Good||Tableau supports lot more datasources, and has support for getting data from db stored procs.|
|Data Load Times||Fast||Good||Qlikview is faster than Tableau|
|Incremental Load Capability||Very Good||Good||Scripts in Qlikview give it the edge.|
|Offline access||Yes||Yes||Extracted Data snapshot is possible for both. Qlikview uses its desktop software for offline use. Tableau has a free Reader for offline use.|
|Columnar DB||Excellent||In-memory Data Engine|
|Vendor||QlikTech||Oracle is OEM partner for Tableau|
|Sales Team||Asks 1 million questions before answering your question||Does answer back||Will prefer dealing with Tableau sales over QlikView sales|
|Best for||DV, Drilldown||Visual OLAP|