I can't tell you how good an outdoor antenna is compared to ANY little inside antenna with an amplifier. Absolutely amazing. If you can install one with a rotating mast that's even better.
Two things to consider: The antenna cable must go through a grounding block which is bonded to the same ground as your home before entering your home's perimeter. Not another ground rod, or water pipe. Second, because you run the risk of lightning entering your home I strongly recommend the use of a coaxial surge protector ON the grounding block, like this gas discharge unit.
Because of this, it's a good idea to check where you have access to a house ground before committing.
OTOH, a half way decent middle ground is an attic mounted directional antenna, which doesn't need the grounding/surge protection.

