Just had my first* Pendo ride - very nice, easily the best train ride I've had! I also had a surprise waiting for them: a bicyle with no reservation (I hired a bike in Kendal, got a bit lost, returned after the bike shop closed, so had to take it home). I can now see why VT require reservations: a staff member is needed to unlock the storage area with a key (and to let you exit at your destination).
Anyways, after hearing all about 'em here, I wanted to try one myself. Regarding lighting, looks very similar to the Voyagers to me. Windows? I find the smaller size gives a more intimate view of the landscape - I didn't miss the larger Voyager windows. Noise? Very quiet apart from occasional rattling (I have no doubt the Voyagers make the same noise, but you can't hear it over the diesel engines!). They were also doing regular trash collections (on both my Voyager and Pendo rides today) which is the first time I have seen that done.
* Pretty surprising, given my local station is a WCML station, but I'm cheap - I only buy off-peak tickets, so I've always ended up on Voyagers, which do most of the off-peak work.