IMO the yellow one's a really ugly bike. Most FS are if we're honest. (The white one's better tho).
SC lost it for me way back when they started diversifying the individual frames. When I bought my Blur, there was only one kind of Blur. It was easy! Superlight - Blur - Heckler: pick one go ride it.
(Yes I'm an old fossil).
I'm firmly in the 29 camp on wheels but I'd buy 650b over 26 any day and I can see how it might be the best tool for the job over 29 for some kinds of trails and riding styles.