Woah, I was spot on! i guess the 168 SL really hates the
sluggish of the acceleration from the Voith B9TLs. Instead of 6
initially, now left 3008K & 3009H only. 
7570B is still on 17 today though. 
And do you know 3029A & 3006R is replacing which of the
Wrights and their duties? I know 3031S is replacing 7570B after
this entire week on 7570B's timing (but I forgot its original duty,
should be 5A?).
Service 17's elderly passengers seem to like the idea of having
full low floor and more elderly seats when I took 3006R on 17 just
now. 
But then, the Voith-ed Wrights' 1st gear
acceleration is really lethargic, there's like a 2 second delay
between the BC stepping the accelerator and the bus actually
moving. Much like a VO3x, but I can say even worse than some of the
CDGE Voith B9s.
But I can't complain much, 17 gets practically Wrights that are
a year younger then those that left. 
3006R replace 7561C 3029A replaces 7573T SBS3031S like what you
said is replace 7570B
