I hear the new Acela seats are straight out of Torquemada's dungeon
I found them quite comfortable in December the last time I rode on a new Acela (funny thing, I was in the exact same railcar northbound and southbound, though not in the same seat). At least, I found the first class seats comfortable. I haven't ridden the new trains in business class yet because I have upgrade coupons. This Saturday I'm on a new train northbound and an old train southbound. Right now I'm booked in business class, but I have more upgrade coupons I plan to use (can't redeem them until 48 hours before travel). Timing is just right as those coupons expire on March 1.
One thing that was kind of nice on the way home was that the tray table had a fold-down cupholder that worked independently of the table. If you want to leave the table closed, you can flip down the cupholder to hold your drink. It worked quite well with a stemless wine glass. Nice idea that that airlines could certainly adopt.
Edited to add: And for those who are interested in such things, it turns out you can't use an upgrade coupon if you have used any other sort of coupon. I had a courtesy $25 discount Amtrak had sent me when the train was half an hour late last summer; I also had a $100 voucher they sent me when it was 18° and the the heat wasn't working out of DC until we got to Baltimore. I used both of them for this Saturday's trip. The $25 coupon disqualified me from using an upgrade coupon. I thought about having the guy reverse the coupon so that I could then upgrade, but he said there are no first-class seats available for the Saturday afternoon train home, so I decided just to see what the new Acela's business class is like. Yeah, I lose the upgrade coupons. Oh well.