I have the larger shark rotator and absolutely love it. But because of some neck issues I can't always handle the bulk of it, so I got the rocket, after reading reviews I was ready to have a bad experience. I was able to vacuum my whole home 1200 Sq ft. Using the various modes as needed.  I was able to run my rocket vac 45 minutes before it shut down! I am more than happy with that performance. Possibly a long run time because  I DO NOT have carpet?  Having a dog (lab) and long haired cat I found carpet to be too annoying to keep clean and allergen free. 
I did allow the vac to charge for a full day before using it the first time. Maybe that matters.