Let me preface that I am a comfort snob when I travel, my vacation on Amtrak is the vacation, thus I always book a deluxe bedroom.
I travel as a single so keep that in mind. I have no referance as to two in a roomette.
For me a roomette is far more enjoyable than coach (let me hear it from the coach crowd, you know who you are!!). But... The rooms are very small. As a single they have room to put your feet up on the other seat and be quite comfortable. For two I believe the the space between the seats is less than desirable. Remember that with two in a roomette one of you will be travelling backwards (facing opposite the direction of travel) for some that is uncomfortable.
The most important is when the beds are down. There is no extra room. To get into or out of bed can be done with the door closed. Don't expect to have enough room to change into night clothes without occupying a portion of the hallway. It is wise to change in one of the community restrooms then return to your room.
I take the CZ more than any other of the western routes and would remind you as others will, there are two sides of the train and the best way to see is from the SSL, not from your roomette. Get out meet people in the lounge, the diner, and at stops.
A roomette may be small, but the train and the experiences along the way, are large.
Enjoy your trip. Most find train travel enjoyable. I hope you will too.