I understand your question and a lot of the noise we deal with is not due to powerline issues, although they can certainly cause high noise levels on HF. I have had those problems and been lucky to have the power company fix it as well. Much of the noise we get today is the result that every house is loaded with consumer electronics that have cheap, noise emitting switching power supplies in them that are kicking out hash on the RF spectrum. The power company can do nothing about this, and our luck at solving these issues may or may not be solvable.
Over the past couple of weeks I discovered that I had a S5 to S6 noise on 144.200mhz in certain directions that was still affecting reception up into the satellite portion of 2 meters. Flipped a few circuit breakers in the house this morning while everyone else was away and tracked it down to a Keurig machine we bought over Christmas last year but rarely use now. Unplugged it, and problem solved! That is one success story, but what if it had been in the neighbor's house instead? That may or may not have been something I would have discovered, or if I had discovered it, something that could have been sold. Even in less dramatic cases, the noise from all of these power supplies adds up to a higher noise floor than what we had before. I am always amazed what I can hear when I go mobile and get out on rural interstates-CW signals that don't even move the S meter come through crystal clear because there is no noise floor to deal with on the higher bands.
I have a Kenwood TS590SG and the noise blankers on it aren't anything to write home about. It probably does well on ignition noise, and turning both of them on does lower the noise floor a little at times, but not near as well as the noise blankers in some other radios. The noise reduction sounds nice in the TS590 but I have never been overly impressed with noise reduction circuits, be they AF or IF, in reducing the effects of RF based noise. Amongst other things, I have never owned a radio with IF-DSP where turning on the noise reduction reduced the S meter reading for the noise, where it should if it was really taking out the noise. Maybe I just haven't owned the right radios. I didn't find the noise blanker in the Icom 7300 to do much on the RF crud I get in my area, but others think it is fantastic. I live in a 1940s neighborhood where the houses are really close together, like maybe 10 feet between the houses on each side of me.
As was stated earlier, I have also heard very good things about the noise blanker in the Ten Triton IV. The Drake TR-7 is also supposed to have a super noise blanker. The downside is that both of those radios came out before I was licensed (in 1980) so they are really showing their age and are very limited in features compared to today's radios. I have never used a Kenwood TS830 like was mentioned before, but the QST review for the TS530 mentions that its NB took out any powerline noise that the author had at his QTH so that sounds promising.
If you read W9KNI's eham review of the Elecraft K3 (it is the first review of that rig) he heaps praise on the noise blanker and noise reduction for that radio. Reading other reviews of the K3 might confirm his findings. Prices for the K3 on the used market have really been dropping recently. The Yaesu FT891 and FT991 have pretty good noise blankers in them that get pretty aggressive on distorting signals if you turn them up a little too high. I haven't used a FTDX3000 so I can't comment on its NB but I don't think it has as many settings as the 891 and 991 do. The noise reduction circuit in the FTDX5000 gets praised in many eham reviews of that rig.
Noise is such an individualistic thing you almost have to try out different rigs at your QTH to see what works on it and what doesn't. It really helps if you can borrow different radios from a few local hams to get an idea as to what will take out the noise you have.
73 John AF5CC