I use them alone and with regular watercolors, and sometimes even just as pencils. You can buy the higher quality ones, but you can also buy the cheap student grade ones. Both work and work the same, with the difference (to my eyes) being in saturation of color. There are also “pencils” that have no wooden sheath in watercolor varieties.

Derwent makes some very good ones – in fact several lines that work with water if desired.

Be aware that their Inktense is a bit different than most others. Inktense works like very saturated watercolor pencils until wetted; then when dry they are indelible, like colored India ink, so you can watercolor over them without creating “mud”. This is an advantage for certain styles of work.

I use both Inktense and a cheap set of General w/c pencils. Both mix in a painting with other media pretty well.

There are now several very good lines of watercolor “crayons” out there too.

Any of these pencil or crayon formulations allow you the ease and precision of drawing or detailing that is much harder to master with a brush for most folks. That, to me at any rate, is their primary advantage.

Thank you.

Do you know how good are the different lines of faber castell watercolor pencils?

Haven’t tried them.

In my local art store they always have a pad (and usually water brush handy) for you to try out these materials.

I think they’re considered student quality and so not as good as the Albrecht Durer but of course less expensive. They may be not just less intense but also may be harder to dissolve.

I don’t own them because I already own the AD, but people I know who own the caran dache supracolor often say that they’re the best compromise for a colored pencil that works well wet or dry.

Watercolor Pencils are certainly NOT ridiculous and are a recognised art medium.
Ive been using both Albrecht Durer watecolor pencils, and Derwent Inktense pencils for years and love them both, especially the Inktense. Inktense has saved many a failed watercolor painting for me.

The Albrecht Durer are a high quality watercolor pencil with good color saturation, and you can lift some of the color off after it dries, if you want to. The Inktense have far stronger colors but of course once the color dries its there for good.
You can use both brands by themselves or with watercolors. I often use my Inktense for details and to add linear mark to watercolors.
If you are a beginner with watercolor pencils, I would recommend both brands, although the Albrecht Durer would be easier to use until you got more used to the stronger, permanent color of Inktense.

If you check out previous months Watermedia Challenges, you will see where Ive used Inktense many times in my challenge paintings. If you click on my Blog (in my signature line), Ive also used Inktense in many of my paintings there also.
I hope you find this helpful, and Im happy to answer any further questions.