The filters are a to-die-for feature! I'd want that. As of the moment I'm using something from Tampermonkey that can add some filters but all it does is grey out some posts. It will be nice to see more intuitive and in-depth filter options. Something that functions properly, like those in shopping websites. Where you are provided multiple filtering options that you can choose to use in any combination possible.

Having an option to change the number of columns in your feed will help those with larger resolution screens.

If you can add in color options that will be nice too. I've seen some websites that allow people to switch layouts and colors freely with 2-5 options available for them.

Post view is a pain when you make graphics - you have to make sure to make it less than 670 or so pixels to make sure they won't reduce the size of your photos and graphics. The uniformity is appreciated though, since I know definitely that all people will see the same thing I'm seeing. But I'm sure we can add other things into a screen's real estate without cluttering it. The post view will not look so much barren/boring if you'd add a background image or a colored background (that users can set themselves probably), and just add in a content box for the post itself. If there's extra spaces on the sides then automatically show up a sidebar (which users have the option of setting up on their own as well).

Just some of my thoughts.