Hey Ultranerd,
I also noticed something similar and opened a thread some days ago.
Meanwhile I thought that it might just be my false impression - and that it´s natural to not have much details in renders with small size like 2000 pix.
But the more renders I make with the Corona 4 Beta daily build, the more I guess that your impression is correct.
Despite, I also find the antialiasing very poor !!!
In previous Betas like Core 1.7, I cannot remember to ever have noticed such problems, even not in small renders with lots of denoising and small number of passes.
Corona-team... Any idea what's going on here?
I'm doing renders for a client right now and really struggling with the problems mentioned.
Also maybe another bug: metals with scratches need a huge time to render clean... as mentioned by another user in a thread some days ago.