The levelling roulette is nearly always worthwhile exp...

Last one I did we got titan story I walked out with over 1.5 million exp for a 4 minute duty.

All the low level stuff pays off.

In heavensward for example getting sastasha would throw you an 750k exp bonus at the end if you were level 59.

If you ran the library at 59 you only got about 850k from it and it took longer.