Well I can say with experience that, at this point in my life, I have drilled thousands of holes in concrete. Mainly for concrete research at work. Ive used battery powered units (DeWalt) and several plug in varieties. Three variables in this equation. 1. what type of concrete your drilling into. 2. impact energy of the hammer drill. 3 quality of the bit.
Normal (current) residential concrete will be around 4000psi with higher end concrete approaching or exceeding 5000psi. The newer the concrete typically the better quality it is (advancement in technology at the batch plant). older concrete or in rural areas you might have 3000psi. So, concrete is not just concrete. Same as sawing soft woods versus hard woods. Soft stuff (3000 psi) will go faster.
little hammer drills and cheap ones don't have the impact energy to bore their way through like the big guys. Something with 2 ft-lb or higher will make life real easy
Get one that uses an SDS bit! SDS is a quick connect style for max torque. BUT the drill has to be made for SDS bits! For an SDS bit my favorite has been Bosch ($15-$30). If you want super high tech get a Hilti bit. They are hollow and attach to a shop vac = no dust. ($100 each)
One hint with the bigger hammer drills they can snap off skinny bits in the concrete = lots of curse words and misery getting it out. Advance about one inch at a time, pull the bit back to clear the flights. Then go back to bite off another inch.
When drilling holes for tapcons, the corded Makita (2.1 ft-lb) I use can drill a perfect hole with the full 7 inch bit in maybe 15 seconds.