[infinite_snoop]

I'm doing a lot of SAP/OpenUI5 development at the moment and performance seems good. I believe the .war is only needed as a one off if you need to deploy the UI5 libs to a Java server? I'm deploying to SAP systems which already host the libraries so I haven't had that issue. One click deploying from Eclipse is built into the UI5 plugin.

UI5 obviously has the weight of SAP behind it (be that for good or bad!) and new releases seem pretty frequent. For developing web apps to consume SAP data at least it seems the obvious choice (it's very much geared towards consuming oData which SAP Gateway provides).