First of all thanks for such great feed reader!
I have two suggestions:
1-Add dock feature in later versions (something like my steams in feeddemon)
I think this feature is very useful
If you decide to add this,Please allow users to set update frequnecy and other options for customizng that (unlike feeddemon)
2-Please add more styles for reviewing new feeds (again something like feeddemon,butter better than that..because i believe you give the bests to users)
It's better to collect all good features of other feed readers + new features in Quiterss!
I forgot this:
Please add a multiple category feed feature in a new subsription wizard for one site...
It means when a person just wants to inform latest posts from special categories in a site (for example in softpedia just tablet/news & windows/latest downloads posts) , he/she has a choise to set several category feeds address in a new subscriprion wizard
Softpedia provides individual feed for every its section.
Please, choose those you needed and add them one by one.