What I love about the short time sketch is you can't over think. You have to jump in head first and go for it.
And then sometimes people go meh over my long hard work and go bananas for the short stuff. And I can see why here. I see confidence in lines, no time to over think or over work. And you got the important stuff in.
I like it!
The short stuff is also ultimately more rewarding and effective. I can dish out 30 sketches in 30 minutes, even if I have a bad day, there will be at least 5 or 6 among them that look way better than I can reliably produce. OTOH, starting a 10-minute sketch, just to realise after 5 minutes, that some of the basic lines are just that tiny annoying bit off, and then either having to bite my lips and prowl on to finish with a sub-par result or scrap it and start all over...
I know I could avoid a bit of that hardship by returning to pencil, and just use the ink for final rendering, but on the other hand, once the eraser is out in force the relationship between effort and final quality still suffers a lot.