Performance of "Conditional Widgets" and "Custom Post Widgets" plugins

I’ve inherited a site which uses both the “Conditional Widgets” and “Custom Post Widgets plugins, and seems to be suffering performance issues as a result.

My site has 73 “Content Block” widgets created with the Custom Post Widgets plugin, which are then controlled by the Conditional Widgets plugin, keying on 22 page categories.

With that many conditional widgets I guess it’s not surprising that there’s a performance cost: pages containing the sidebar in question take about 10 seconds longer to load than pages without the sidebar.

My questions:

Has anybody else seen this problem?

Is one of the plugins to blame, or is it likely to be the interaction of the two?

If I had to guess, my suspicions fall on the Conditional Widgets plugin. Is there some other plugin which can do the same thing more efficiently? Watching a screencast from the author of the Custom Post Widgets plugin, Johan van der Wijk, I see that he uses the “Widget Logic” plugin. Is there a reason to believe that Widget Logic would be more efficient than Conditional Widgets?

Finally, is there some other approach entirely that I should consider? For example, rather than checking all 73 Content Block widgets on every page load, maybe there’s a way to have the content of the page itself indicate content to display in the sidebar. Hm.