I thought I remembered someone saying it isn’t because only low end signal goes there but has anyone done this?

 

They're correct about low-frequency, at least in the ML system.

But even in the ML, replacement of the front lower speakers was worth it in my opinion. Much better base response than stock. I went with Rockford Fosgate R169x2 in that spot but I'm sure the Kickers would also do a fine job. I used the Kicker KS series 3.5" for the other speaker hard points.

 

I have a 2020 ES non-ML and the speakers I ordered from Crutchfield was suppose to fit. They were not even close. They were WAY different than any aftermarket speakers so I just sent them back and left what I had here.

 

They weren't the same in the ML equipped vehicles either. The bottom front speakers are more of a 6x8 rather than a 6x9. Crutchfield provided an adapter mount that worked fairly well to mount them correctly though I still have to make a few holes in the mount to fit the ones in the door.

 

I went ahead and did it. Definitely worth. As others have said, the difference in weight & mass from the stock is almost laughable.
Crutchfield said they fit but in hindsight I should have gone with a round option rather than 6x9, for a potentially more seamless install. I had to trim two tabs at the bottom for the door panel to fit back on, and currently only have 3 screws in. I shimmed the one corner without a screw with adhesive felt pads and it was pretty snug. I don't notice any vibration or rattling so I'm okay with it.

Also, the Toyota Metra wiring harness for $10 is 100% worth it. Snaps right on, no cutting or splicing needed.