i think speed & performance should be on the top 3 priority list for tt-rss .. we know tt-rss is already very well built rss reader in term of features & UI.. we can improve it further..
I agree that any opportunities for performance enhancement that can realized in the core application should be taken advantage of (as fox as done here). That said, I feel I can comfortably assert that most of the blame for any perceived or real performance degradation in tt-rss is likely due to the database and operating system and not the application.
This is not to say that PostgreSQL and MySQL perform poorly, or that Linux is a poor choice of operating system (quite the contrary). Rather the database software as installed by hand or by a major Linux distribution is tuned very very conservatively. Running tt-rss for any appreciable length of time with a moderate number of feeds will quickly require more memory resources than the database software provides out of the box (certainly the case with PostgreSQL).
In addition, most Linux distributions (certainly all the popular ones, even server targeted distributions) have their disk I/O tuned for "fairness" and/or for responsive desktop use (the cfq block I/O scheduler, in my experience, is terrible for databases). After reviewing a lot of Linux and PostgreSQL performance tuning information online and experimenting with various settings, tt-rss absolutely flies on my server.
And when I say "server" I mean "6 year old Dell business desktop PC" (it's a Pentium 4 HT Dell Optiplex GX620 with 4GB of RAM, only 3.5 of which are actually usable. The disks are "super speedy" 5900 RPM jobs). The difference in performance when using tt-rss is night and day. As if a shiny new modern server had been dropped into its place.
So while, as I said, I agree that any opportunities for performance improvement in the application itself should be seized, I think a lot more emphasis needs to be given to basic Linux and database performance tuning skills before blaming tt-rss itself. And in the case of article content slowing down one's browser, well, garbage in, garbage out. No amount of tt-rss platform performance tuning is going to polish a turd like Flash.