Hi,
Although I live in the UK, I have travelled many thousands of Amtrak miles in both coach and roomette. I am now 59, and spent my 59th birthday a few weeks back on board a silver service train, in coach, from Washington to Orlando. It was fine.
The longest coach ride I did was 2 years ago, from Sacramento to Chicago, and strait on to New York the same evening. Once again it was a great experience.
I believe it all depends what you want from travel... for myself, there is an element of adventure and a large degree of "local flavor" in coach, and I have met some great characters:
A cage fighter, a woman just out of prison, a keen hunter, a gambler, an Amish gent who talked to me for ages about his understanding of the world, all human life is there.
It's real folk, travelling from A to B for a reason, not a rail cruise for train fans...
I like the big seats, and being 6 foot 2 tall, it is nice if I can get the two seats to myself at night, not something that might happen often in the future, given the rise in ridership.
Roomettes are excellent, but often cost a lot more, and it is great to sleep flat out too. One has privacy in a roomette, and one can choose to be sociable in the lounge car if desired.
It all comes down to why you are on the train? You pay your money and make your choice, but I feel that coach travel gets a worse reputation than it deserves, here on A.U...
Cheers,
Ed