I had a fair amount of problems doing this challenge.
The number of details I finally wanted to be was difficult for my machine.
Dragging vertices slow at 3 million faces.
I had troubles switching tools and brushes. Each with their different strengths and options.
Couldn’t get sharp edges. But I think, that is more the inexperience part of doing this.
But it was really fun to do. Difficult to say, it’s enough. You know "Less is more " …
Great job! It’s looking good! 
It’s looking pretty good!
Maybe it’s still unfinished, but I found that you put details in unexpected places: for example, I think that the lines on the thighs should be on the outward side instead of the inward one you placed them in, as usually the thicker and rougher part of the skin is the most exposed
About the strain on your machine, while editing, have you tried to cut the mesh in smaller parts, like splitting the head from the rest of the body and editing it by itself (I haven’t tried it, so maybe nothing changes)?
great job, bro
Yeah thanks, for pointing out, inside outside roughness. Point is, to make blood vessels I need a very high dyntopo setting. So I did some random ‘paints’. Just to do something … but it’s more an option for normal- and bump maps. And I keep changing and tweaking the mesh. Without any plan. I even don’t use reference photos. Just want to focus on the sculpt process and tool, techniques.
Yes, I also thought about splitting the mesh in head, body arms, etc.
But I want to follow the steps in the course. And not drifting off, into other parts on the ‘unknown’…
Like the horns, which I did in my own way. Which led to problems.
Also here, the basic design concept of Blender, still applies here.
Details are less important when no closeups are involved. Like, zooming in on the head.
I spend some time in modeling the horns, who will see it …
Work from low poly to high poly, etc…
The most bad parts are the hands. Here some real improvement are possible. Maybe this afternoon, when I got some inspiration … 
THX, have fun, and go render something.
That looks really great, doubly so in light of your struggling machine.
