Since this topic is not closed / marked as resolved, and it's the only recent one I found in PL support forums concerning backend performance issues, I am taking the liberty of asking a few related additional questions here. If it's not relevant, forgive me and tell me if I should post somewhere else.
Actually, I obviously have a problem similar to the one exposed by jdoughall, i.e. an amazingly slow admin with Pagelines compared to Twenty Twelve for instance, using a shared hosting service with a 80 Mb RAM limit for PHP processing. For my information, did you solve your problem and how ?
1. I read this topic (and others...) very carefully, followed indications, and my finding is pretty weird (if you consider I'm let's say 7 years old...). Actually, PL backend with no plugins at all is more or less as fast as any other light theme (vs. framework) like Twenty Twelve. BUT, with a dozen of well known and "essential" plugins (Jetpack, Disqus, BackWPup, Google XML Sitemaps, Wysija Newsletters,...), Twenty Twelve backend remains fast, whereas Pagelines is dramatically slow. And, once again, I speak of backend : no significant difference for frontend (tested with Pingdom, GTMetrix,...).
Hence : does it make sense for you ? Maybe PL creates more "conflicts" with plugins, in my poor shared hosted environment ?
2. I read many different assumptions pertaining RAM requirements for Pagelines in the forums. Are my 80 Mb enough for my very minimally trafficked site, or not ? Could it explain moreover these specific backend issues ? Oh, and, if I read well, do I have to define in my wp-config the WP_MEMORY_LIMIT to 64 Mb or 96 Mb (if 80 is really not a good value) ?
3. This said... I'm now 3 years old and a bit lost. I created a CloudFlare account, linked my server to it, and activated ALL CloudFlare optimizing options (beyond plain CDN --> ), i.e. compression, "Rocket Loader", and so on, including HTML / CSS / JS minification. And then suddenly not only my frontend performance rocketed, but my Pagelines backend too... Is this logical ? Any hint / explanation !?
Many thanks in advance :-)