I recently changed my Bongos stock strings (45/100) for heavier gauge strings (50/110). In the past I also used to have heavier gauge strings, which have, to my opinion the following advantages.
As they have more tension, they can bring the neck of your bass in a better relief, so you can have a really low action without audible (when plugged) fret buzz. I really felt a difference on the Bongo, being able to get the set up I want.
With that extra tension, they are also recommended if you play downtuned (D or C instead of E).
The sound is also deeper and they wont break as "easily" as lower gauge strings.
You wont feel any difference in playing comfort if the change is reasonnable (100/110...) ; of course if you put a 130 instead of a 100 you'll feel its bigger and will have to get used to.
I use roundwounds, generaly EB or rotosound (those have more tension).