Professional photoprapher and longtime lightroom user.
I mainly use a combination of bridge/lightroom for categorizing my images into projects before sending them into their respective project folders to be made into PDFs for book/portfolio/etc projects.
I know that LR is capable of creating presets in the export interface, I just wish that there was a way for collections to have their own individual export settings. What I mean is when you right click on the collection you are able to assigna an export destination per collection so there is no need to have to re-assign or find the folder every time you need to export images. Don't know if this is something that is possible, it would be a nice time saving feature for a user like myself.