Our ears get adjusted to the effect a boost has on our amps. When I used to boost, my amps didn't sound great without the boost. After a little time my ears adjusted without the boosts. Some amps need a boost but not a 5150. It's a matter of your preference but you should play your amp without a boost for a good amount of time and see what you really prefer. I prefer without a boost if the amp has enough gain and is tight enough on it's own. You get better dynamics with no boost.