On 2015\02\28 10:56, Paul Corfield wrote:

I expect the NB4L will always remain controversial. I don't use them
because they are so noisy they give me headaches and make me ill. I
rarely get headaches so for me to get one requires something
"special". Every time a route converts to the NB4L another bit of the
bus network is "shut off" for me. Call me stupid if you want but no
other bus makes me ill.

Wow. I don't think you've mentioned that. That's a scandalous flaw.
In the bus, not in you!

Thanks to everyone who's commented.