I recommend doing some internet sleuthing here in the brush forum. You will find people's impressions on that size and HMW. Do searches on ben73 and drP in particular. This thread is old but whitebar's advice (Post #9) is very spot on about Plisson. Plisson - Worth the cost?
Myself, I happen to have a Size 20 2-band HMW and a Size 18 as well. The brushes perform excellently in creating lather. The high loft of the Plisson and the shape of the knot just really excel in lather generation. These are older brushes, and for the older brushes, especially if you get back to the 70s to 80s stuff is truly phenomenal.
What I like about mine is the horn material is just how I like it, and the shape is just classic shaving brush material to me. It functions, and the fingertip feel of the brushes is wonderful too. The lather generation of the brush is great, and i like the large knot feeling on the face. I particularly enjoy the painting motions with these. They're not meant to be scrubby or density when you use it. There's a Chubby for that. That is not to say that a Plisson is floppy, as for me it is not.
When it comes to recommending buying it or not, that's a harder proposition. They are not cheap, that is for certain. You could buy quite a few brushes for just the price of one HMW #20. If you can tolerate the price they are a quality brush and have been around for a long time for a reason. I would be much more inclined to buy if I can see individual pictures of the brushes before purchase new. I have no problems buying used, and as a result have gotten mine at easily half off and have been well satisfied as I've seen what I am getting before hand. If you're okay with used and can find one that size I would recommend it without a doubt.
View attachment 908788
Plisson 20 on the left, Plisson 18 on the right
I thought maybe a photo would help. The right one looks like a 3-band, but it is a 2-band. I like to call it a 2.5 band. Looks like a 3-bander and splays a bit like a 3-bander, but it still has more backbone to it similar to a 2-band.
Gorgeous!View attachment 908788
Plisson 20 on the left, Plisson 18 on the right
I thought maybe a photo would help. The right one looks like a 3-band, but it is a 2-band. I like to call it a 2.5 band. Looks like a 3-bander and splays a bit like a 3-bander, but it still has more backbone to it similar to a 2-band.
View attachment 908788
Plisson 20 on the left, Plisson 18 on the right
I thought maybe a photo would help. The right one looks like a 3-band, but it is a 2-band. I like to call it a 2.5 band. Looks like a 3-bander and splays a bit like a 3-bander, but it still has more backbone to it similar to a 2-band.