Yeah, it is a little small. I've been doing the actual work at 5000x3300, but for uploading, I shrink it down to 3000x1941 before saving. I might upload a full-size JPG or two as I get closer to the end of the rivers. I'm probably at 75% or so, right now. A few of them could use some work, though.
And I think I'm going to play around with the oceans, anyway. They don't look wrong, per se, to me either, but I feel like I can do something different with them. I'm planning on extending this out a little, anyway. I'm going to expand the Eastern oceans a little, and do some stretching, and convert it to Equirectangular at some point.