Bill Zebub
“It’s probably Matt Mercer’s fault.”
That's fine. You get to play how you want.
But the answer stands - I prefer the choice to be more informed by the in-fiction presentation than mechanical metagame information.
The 5% difference is below what humans can reliably notice without keeping detailed records and doing some math. Indeed, at that level, I should see more rumors of supposed magic weapons that actually aren't magical than rumors of ones that are!
ACTUALLY...
(ok, pedantry off) a +1 results in a much greater damage increase than 5%. Maybe still not noticeable without careful record keeping, and even then you might not know the difference between "it would have died anyway" and "good thing I have a magic sword or it would still be alive with 1 hp."
But it's more than 5%.