I believe I have some whitepaper somewhere that evaluates web performance vs citrix performance.
The crux of the matter is that the packets delivered in a different way between web and citrix - a different methodology.
With the web, its very similar to any event driven application - you see packets only when the client is being used. There can be long periods of inactivity, followed by bursts of activity - where large amounts of data might be required. On a WAN with high latency, each of those packets require that the previous packet has been acknowledged - so its very serialized. Helping increase the browsers maximum threads from 2 to 10 certainly helps - but fundamentally the code will still wait for prior packets to be acknowledged.
Citrix (or RDP), on the other hand, is a streaming solution. Video and keystrokes are streamed. This means that citrix can be more intelligent around latency - that it can "skip" screens or graphics with no loss to user perception - or can reduce the overall look and feel of the screen thereby reducing traffic, but not reducing the user experience.
But a bigger concern in deploying a web solution is the management of the browser, as mentioned before. Deploying the URL directly to large numbers of web users will require support at the browser level - which is not only tedious and expensive, but can also be dangerous due to the amount of malware and spyware out there currently. Even Yahoo toolbar has been known to cause issues with EnterpriseOne.
Not only that, but the deployment of SSL across your network requires even MORE resources and can also be relatively expensive. Citrix has icasecure - encryption built in, so there is no requirement for SSL since the web packets won't travel across the network.
Deploying the browser through citrix, and ensuring that the user can ONLY go to the JDE site will reduce the impact dramatically of browser support. You can enforce policies on the citrix browser or even utilize a different product (like Pastuhovs OneBrowser).
Lastly, remember that the Java web client also needs a significant PC to work with. Don't think that the web client is "thin" - there is a lot of code that processes locally, and it requires significant local resources to work correctly. By deploying using citrix, you won't need to upgrade your users resources - and can take advantage of centralized server resources.
I recommend going with Citrix or Terminal Server for publishing the browser for any customer that has any size wide area network. It just makes sense. You can get significant numbers of users on a terminal server when just deploying the browser. I also try to set that expectation (unlike Oracle) as early as possible within an upgrade.
