If you’re using OpenImage Denoiser then there is no difference in the result. The one in the properties panel and the compositor node both use the same, since 4.1, I believe, the properties panel OpenImage can use GPU though, which cuts down the render time slightly with the compositor using CPU and being so slow. Not sure how it is in 4.2 now with the ability to switch to GPU.
The main difference would be that, hardware depending, you could switch to Optix denoiser in the properties panel, if you have an nvidia card. I read a bunch of times it’s better for animation with fewer artifacts, where OpenImage is better for stills.
If you want to use OpenImage and have a capable GPU and use 4.1 or higher then I’d activate it in the properties panel. With 4.2 that’s open for debate. Optix is only available in the properties panel anyhow.
