There is more to electronic noise than the THD. Power factor also comes into play. The OP's bulbs seem to be pretty good with a
Power Factor >.90. Many of the cheap ones are not Enerystar rated have a power factor ~50%. That means that half of the power going in is wasted and the unused "power" is dumped into the neutral leg. And while the THD: <35% does not sound that good hopefully it is much
<35%.
A good bulb can be ~ 10%. But generally if a good manufacturer cares about their design power factor and THD are both optimized.
So the take home message is you should look up the specs before you start swapping out your incandescents and don't buy the cheapest dollar store brand bulbs.
So the take home message is you should look up the specs before you start swapping out your incandescents and don't buy the cheapest dollar store brand bulbs.