I'm really curious about the noise and vibration levels in these.  Certainly the conventional buses in Milwaukee are very loud and suffer astonishing levels of vibration (which rattles the interior, contributing to the noise).  If anyone actually cared what the passengers thought or wanted to attract those potential passengers who could always just choose to take their cars a quieter, smoother ride would help.
These newer buses are much nicer and quieter (inside and outside) than just the last model that were supposed to a vast improvement over what we used to have.
In the US buses are normally underinvested.  It's the bottom of the municipal budget when there is capital spending to be spent.

Consider who rides in them: working class people who don't own cars, or are not able to drive for medical or other reasons.

This is a group of people who are used to getting second best in life-- nice buses is hardly top of the list for some Filipino nanny or Afro-American housekeeper or a mental health patient (that latter from a friend of mine who didn't have a valid US license for a while (UK driver) who took the bus too and from Berkeley where he was studying-- talking to his fellow busmates).

They are hardly going to have a loud political voice against overstretched city budgets.

In Toronto there is an extremely affluent neighbourhood (Post Road in North York) where the houses run 5-$10m.  The ratepayers wanted to do away with the bus service that ran up there streets, until it was pointed out to them that their maids and nannies used it to get to their houses.

Of course, it's a downward spiral.  Bad buses mean fewer middle class people use them, which means services are cut, which means fewer people use them.

That death spiral has killed public transit systems all across the world.

It is sobering in China to see how they are throwing away their bicycles, and how you only use the bus if you have no choice.  The car is the thing for the aspirant middle class, and already the traffic in most major cities is killing.

In 50 years time they'll realise they made a mistake, just like we do, now.