Then I discovered the Pentel Multi 8 lead holder and ordered it.
Here's the package the Multi 8 arrived in:
It comes with the lead holder itself already filled with one of each of the 8 colored leads, 2 replacement leads of each color, a sharpener, and the manual.
Like the Pilot Color Eno pencils, this is a Japanese import. There is a similar product on the American market called Pentel Arts 8 Color Automatic Pencil (some people I've seen refer to it as a Bible highlighter). Both seem to use the exact same refills. There are also violet leads available if you just want to swap one out for it.
I went ahead and wrote the names of each lead color, then colored a small section with just a bit of pressure and almost no pressure, and finally drew two lines with each color again one with a little pressure and one with no real pressure.
It should be noted that the Pilot Color Eno pencils are a .7 lead while the Pentel Multi-8 is a 2 mm lead.
The color Eno leads were a little less vibrant, but again are also smaller leads. The Eno came with violet while the Multi-8 came with brown.
The main different is definitely the fact that the Eno has a different pencil for each color. You could obviously just buy the .7 replacement leads and use them in any .7 pencil. You'd be swapping leads constantly if you wanted to make a multi color drawing, so it's better to just have one pencil for each color. The Multi-8, however, fits 8 leads into one pencil.
The Multi-8 reminds me of the classic Bic 4-color pen. It is a little more complicated than that pen. If you have kids around you'll want to teach them how to use it so that it doesn't end up broken.
The pen clip turns. Put it on the color you want (make sure there are no leads currently out), press the button on top and the lead will basically fall all of the way out to the little metal piece at the bottom of the lead. Pressing the button again and tipping the pencil over will allow you leave just the amount out that you need. The lead will not slide out thanks to the aforementioned metal piece. To remove / change the lead you need to turn the button so that the little line is on the color you have out / are replacing. It will now easily slide out. To replace just leave that mark lined up with the color, slide the new lead in through the bottom of the pencil and continue as usual. I highly recommend placing the lead back up inside after each use so that you don't accidentally try ejecting another color the next time you go use it. Like most mechanical pencils, just press the button on top of the pencil then tip the pencil upside down to ensure that the lead goes back all the up inside of the switching mechanism.
Prices at the time I bought them:
The color eno set of 8 pencils = $ 10.68
Set of replacement leads for the eno: $15.47 (10 of each color)
The Multi-8 with a sharpener and replacements for each of the 8 colors = $22.75
While I didn't buy it, the Pentel Arts 8 color (American version of the Multi-8) was $10.99 at the same time, didn't come with a sharpener or replacement leads. Replacement leads were $14.39. So the American version with the same number of leads would have been a couple $ more and that's without the sharpener.
Which would I buy again?
Honestly, had I found the Multi-8 first, I probably would have never bought the Color Eno set. It's much more convenient space wise. The 2 mm leads give a much more vibrant color. The only real advantage to the Eno set is that you get more leads in the replacement packs (10 vs 2) but the Multi 8 has much stronger thicker leads so I am not sure that's really the advantage it seems.