Curious why you view the Acela lounge as scary. For me, it's a welcome respite from the rest of Penn Station.
I don't think Select will matter much for you. I'm a former SE and current S+ due to my ~20-30 round trips a year on the Acela to DC/BOS from NYP. I value S+ solely for the United Club Access and the upgrade coupons for personal travel, as I generally am in Acela F and do not need S+ for ClubAcela access. If there was no ClubAcela/Acela F access, I wouldn't go out of my way to do S+ status.
In fact, I was at ~18,000 TQPs last year, and didn't feel the need to swap out a flight for a train or spend 10k on my Amtrak credit card to get to SE.. but I would for S+.. but only for the airport lounge access + upgrades