David, thank you for the nice explanation. Indeed, if the page-size is a huge factor it might be better idea to switch to ASP.NET MVC since it provides more control over what is going on the page.
Ian, I just want to point a few things you can optimize in order to fasten your app:
1) First of all, when testing disable debug
mode in the web.config.
The reason the menu is not cached is not because of the master page but because most likely you are testing in debug mode. I suggest that you take a look at that setting.
2) If the scripts are still not cached you could consider using our CDN provider
, which provides very good caching support.
3) Disable the ViewState on the page and always bind the controls in the Page_Init event (this is before TrackViewState occurs)
4) Utilize compression.
I hope that this information helps.
the Telerik team
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