So some thoughts on using the new SBH (these are just my experiences from today and are my opinion only
HUGE advantage to SBH is the fact that it is native/no need to convert to OBJ etc for iray. One can also save the file and go back and tweak to one's content. It does make a somewhat large file- this above scene/file is 11.1 MB (consists of a body SBH and a mane/tail SBH)
End user- def above applies. I haven't seen all that much improvement in rendering times over LAMH myself. But one can of course have multiple haired figures using SBH which is a big advantage.
From a content creator's POV: (and in my case, mainly animals, so "fur" as opposed to a hair style for people)
REALLY missing the ability to have symmetry in choosing areas to generate guide hairs. On the other hand one can do a very quick, down and dirty selection of material zones. In this case, "Coat". In LAMH one can also pick "COAT" (or Fur Body etc) and then deselect the polygons where you don't want guide hairs - that is how I normally start a new LAMH preset for an animal.
Using a paintbrush to select areas to populate hair is weird to me as LAMH one picks polygons using lasso tools. It's not bad- just takes some getting used to- will need to try it with my tablet and see if I can make more refined "density maps"/be able to get more detail there exactly where I want it. But it is pretty fast (again the moving around and zoom is kind of clunky to me tough- I am sure it will get more familiar with more use.)
In the styling I do miss LAMH's ability to use a lasso instead of a rectangle in selecting guide hairs. The zoom/moving around isn't as nice/more clunky somehow- not sure why- one zooms in and out a lot when making these things.
Also I really miss the LAMH ability to just select say "Head" and style that. One HAS to use the somewhat clunky guide hair selection tools within the whole body of the animal which can be tricky. I also miss LAMH's "taper" a lot.
The shader is a bit odd in that I am really missing translucency/that is sort of making me nuts. Also I am not getting the underlying texture map to always "pick up" the way I want. More messing to do
Even after nullifying a lot of settings one still gets a more contrasty look to the hair/a lot of shadows. Def playing with density can ameliorate that to a degree.
Both have the ability to make as many hair groups as desired. Def. LAMH makes picking hair density a LOT easier.
Being able to go back and forth between editing the hair and doing renders is a big advantage to SBH for sure.
Crashing- SNH has not crashed at all for me. I very rarely have crashes in LAMH though. My Mac Pro Tower is 9 years old so I am not using anything too fancy. I DO have a lot of RAM though and a pretty decent processor.
So long story short, as an end user I can really dig the SBH. As a content creator I still prefer LAMH. For myself as an artist using these products, I also prefer LAMH's look better at this point. That could change as I mess with SBH more.
Anyway just some thoughts after messing with both.