I rode the 501A after work from York U to Bramalea to Downtown Terminal, and back to York U, partially on the old Route 1 and on 501 in the evening.
The buses are very quiet, except the ventilation can be loud. The seats are quite comfortable and a bit softer than the Viva seats. Except at the front (the accessible seats) and a few at the rear, all seats face forward in 2s.
I took this picture at night. The interior LED lights are bright (door and headlights are also LED), but they give off surprisingly little glare, it was easy to look out the window at night, unlike say a GO train coach.
When I got to York U, one of the buses was having mechanical problems. This is the first day the New Flyer Xcelsior model has been in revenue service anywhere, so I hope the kinks are worked out.
Luckily, three buses (two 501As, one 501) show up and scoop up the passengers. Buses were busy, but not packed, from York U, even in the mid evening. This route will be a big success.
At Bramalea Terminal. The terminal isn't done yet. The Zum buses are tracked by GPS and there's real-time displays for the 501/501A and departure times for all other routes scrolled on several monitors. The washrooms are much nicer than the dives at the old BCC terminal, and there's a large info/ticket counter and lots of interior waiting area. It's a huge improvement, though it's a longer walk to the mall, and without shelter part of the way.
You can see the dual left turn lanes in the background here, though the right left turn lane from Queen to Central Park and Central Park to Queen are buses-only, which seems to work well.
And yes, the ramp out of the terminal leads right to the Central Park/Peel Centre intersection, with a dedicated light that works quite well in getting the buses out of there quickly, which I saw work very efficiently.
I took the route 1 to see what the old terminal looked like on the way back from downtown (the downtown terminal also has new bus departure screens inside). The shelters were all removed, and it was blocked off by tape and concrete blocks. A sole security guard was sitting there, I guess redirecting passengers and keeping the site secure.
The Zum buses all have digital next stop displays, and scroll times and dates as well as the next stops. The voice is soft in volume, though it's a very mechanical fembot voice like that of YRT/Viva, and does not say the street generics. (ie: "Next Stop: Torbram") A few conventional buses now are equipped too.
I'm impressed for how this worked on the first day, where there bound to be hiccups. The 501 is fast, the queue jumps do work, and the buses are quiet and comfy.