Need opinions on process...

Sorry I can’t come up with a better subject line.

I’m trying to prep a photo for making a vector image out of it. I came up with two different ways of achieving my desired result, but these results ended up being different. Here’s what I came up with:

Techique 1 - converting the image to 5 levels of gray (0, 25, 50, 75, 100%) (took some blurring and sharpening to smooth out some jaggedness)
Technique 2 - manually create 5 layers in 5 levels of gray by thresholding the original image at 4 separate places through the histogram as close to 25, 50, 75 and 100% as possible

Which of the two do you guys think is better? Personally I like some parts from one and some parts from the other. Any ideas how I might combine the techniques to get best from both? Any suggestions on doing this better?

Go easy please, but be honest. I’m a newb in this area.