I have the 1st Generation of the Honda Variable Cylinder Management (VCM) enabled, and the engine is very hard on the oil, with extreme temperatures on the cylinder heads which can cook the oil due to the VCM and a poorly designed PCV valve. A mechanic recommended that I switch to 5W-30 as that would provide greater resistance to the extreme heat on the cylinder heads.
I had moved my Honda Odysseys from 5W-20 to 5W-30 about 3+ years ago, and primarily have been using Super Tech HMFS 5W-30 which is the same oil as Kirkland (both made by Warren).
No issues to report. Oil looks medium brown when changing at a 5,000 mile / 6 month (whichever comes first) oil change interval.
My vehicles don't consume any oil, so no top off oil is needed.
Both the Kirkland and Super Tech full synthetic oils are Dexos 1 Gen 3 approved.
I went to the Lubrizol website at:
https://360.lubrizol.com/Resources/Relative-Performance-Tools
The GM / Dexos 1 Gen 3 Specification scores a 7 for Sludge and a 6 for deposits (Varnish) protection (higher is better).
The API SP Specification scores a 5 for Sludge and an 5 for deposits (Varnish).
So it's definitely a good idea to only use Dexos 1 Gen 3 oils or Euro speced oils. Using plain API SP has a lower bar.
Kirkland / Super Tech are very low priced, and the credit card cash back lowers their price even more.
For my applications, I don't see a reason to use anything else.