they make a big difference. without the tips, if you drive a lot uphill areas or in eco/comfort mode around 100-110 km per hour range ( i guess thats about 62-70 miles per hour ) you will hear drone. above that you are fine. in sports mode you are fine in higher rpms. and this was just me in front
seat and drone didn't bother me. my passengers def heard the drone, but didn't complain. not sure out of politeness or not caring. i had to ask them if they heard it before they confirmed it. you can still have normal convo in car in your normal voice tone, and listen to music. you will hear the drone regardless. exhaust itself is fairly quiet in low speed and low rpm. think cruising to your home or leaving a parking lot you won't annoy your neighbours, but they will know it's been modified. source: my GF knows when i am parked outside her house despite me not revving car or speeding in her street. she knows the unique sound of the car, and her neighbor has modified bmws in his garage.
i understand where you are coming from with a valve off and on system. my main reason for borla was that borla sounded the best out of all exhausts i heard. it's def the loudest as according to 2 other stinger owners when we do meets. one who has an MBRP system with ark downpipe (which sounded great too imo) and one with resonator delete.
for me i didn't want to buy something that ends up being too quite then regretting not going louder. at least with borla i thought if i hate it, i can switch to quieter system. and also out of all the ones i heard online, borla and bastuck sounded the best, but bastuck seems only available in europe.
i wish i took a before video so you can hear drone. i am happy to do an after video so you can hear how it sounds in cabin. remind me in 8 days as i am in quarantine right now lol. and i have decent mics to use since i use them for youtube lol. so hopefully it will sound clear to you