Perhaps a quite boring answer from me yesterday…
The thing, for me anyways, is that there’s a lot of captures that sound very similar. And with the onboard factory captures as a starting point that sound as good as they do (to my ears) I’ve found using various IR selections (also from the factory content) give me more variation than downloading different amp captures.
I do however have found some lovely things in the nano cloud, and downloading and trying out stuff is a lot of fun. (Sometimes knowing what’s been captured makes the placebo effect for me kick in really hard. 
)
Anyways here’s a few pointers for amp captures that I like:
The “FNDR BLBM” captures from amalgamaudio, both the amp and the amp+cab versions are lovely with my LP. Favorite one is “FNDR BLBM NR Clean FAT DI”.
https://cloud.neuraldsp.com/cloud/u/amalgamaudio/neural-capture
And perhaps Tone junkie is hard to miss on the cortex cloud. The “65 Deluxe N Clean” and the free variations of this amp is really great.
https://cloud.neuraldsp.com/cloud/u/ToneJunkie/neural-capture
And for metal and rock there’s good stuff to be found in this thread: