Now that the NABI's are showing up on the 1 bus, which I ride daily - I've had a chance to see how they really work in daily service. Some comments:
So far, they seem to be working well in general, especially when they aren't jam packed. Haven't seen the wheelchair ramp in use yet, but I have noticed many of the seniors having an easier time getting up just the small step instead of the three big ones on the RTS's. Interesting note - yesterday someone requested the bus to "kneel" even for the small step. The driver hesitated for a moment and then found the appropriate button. Then she said 'hmm, i didn't know these busses could do that.' Excuse me? Aren't these folks supposed to have at least some training on the equipment? Isn't this feature something that should be covered in this training? (likewise with the destination signs that some people were commenting about before, although I've had good luck with this so far).
They are a comfortable ride, though - they don't rattle and bang down Mass Ave. quite so much as the RTS's do -- that stretch between Central and MIT is BUMPY! They also have some surprising pep for large busses. I think the drivers are still getting used to this, because when driving away from a stop the bus really jumps out.
The rear doors are farther forward than on the RTS's, which I really like because in encourages more people to use them. I've noticed that people will always walk forward to a door (barring other circumstances) even if the rear door is closer. This really does make a difference in speeding operations.
Some small (or not) comments that could be improved (some more easily than others):
There is a conspicuous lack of a handhold on the very front left of the passenger area (I guess there are some sort of access panels here). But I've seen people try to reach for something over there when they are still walking back as the bus moves forward and grapsing in thin air. Also a problem when running a very crowded bus with lots of standees (as can be common on the 1, especially in the evening rush).
Speaking of crowded busses and standees, the NABI's don't do a great job of handling this. There is a nice big area by the rear door, but then when those doors open they open inward (why????) and bang into everyone standing there. People will eventually learn this isn't a good place to stand, I guess - but it wastes a lot of space.
A suggesting to help this (understanding that a door revamp is unlikely) -- take out the double row of front facing seats on the front right side of the passenger area. I think there is room for three side facing seats in their place, so you only lose one seat. People don't really like to sit two across with strangers anyway, and you gain a whole bunch of standing room in the center aisle.
Finally, I think this has been mentioned before, but there really aren't enough stop request strips. Nothing is really accessible to anyone standing, and from one of the rows (now i forget which one) it isn't really easy to reach, either. Of course the old fashioned way of shouting out 'next stop please' seems to work ok in the event of not being able to reach the strip.