Thats is a very VERY difficult question to answer, especially for
some of us that use Blender commercially.
It’s who get’s the job done with the best/fastest results.
Real cases from my work:
Case-1: The “hero” mascot:
I’m rendering a rather large Mascot made for printing on
a HUGE cinema-poster, I use both Yafray and Blender’s
internal renderer quite a lot and decide to go with Blender’s
internal renderer on this one.
Reason: It’s a gigantic poster! it’s 300 DPI and that
means at least 10800 x 7000 pixels raytraced, shadowed
textured with HUUUUGE textures - and Blender handled this
one in 25 minutes while yafray couldn’t finish over days, and
the deadline was closing up. Cause: SPEED!
Proper ligthing & good textures made it look really good, and
Blender 2.34’s new Texture-OSA made all the difference.
Case-2 “the RAT & the Rodent”
I created a rather sophisticated biker-rat…sophisticated
in the way that it had lot’s of details but few textures.
Rendering it with the internal blenderer is fast, but lacking
textures it’s nowhere near as good as yafray.
Result: Ended up using yafray for this one
Reason: Yafray’s fairly quick with cached lights AND with a
good deal of experimenting with the settings, we could get
quite decent results out of it. And it wasn’t NEARLY as slow
as Case-1 because of the lack of textures on this model.
Lot’s of textures seem to slow yafray down severly.
Yafray also gave it a much better “soft-tone” light - making
it look like “Clay-models”. That looked good (methinks )
While the rat had no textures and could be easily rendered
in Yafray, the Rodent had a LOT of LSCM-Mapped textured.
I’m not sure why Yafray doesn’t like UV-mapped textures
with LSCM mapping in Blender…but it looked terrible
with yafray…weird big chunky blocks appeared all over
the character like a “video-game-bug” but was still somewhat
mapped over it…but with chunky-pixellated-squares, that
wasn’t acceptable so I had to go with the Internal renderer
for this one.
See guys? No way we can settle for just one renderer.