The lower the deck and the closer to the center you are, the less you will feel the motion. We went on the Inspiration and didn't feel anything unusual........you are on a boat and some people feel the motion more than others. My son is prone to motion sickness and, even with medication, he could not go into the gift shop (front of the ship). However, he was able to watch the shows........very front of ship. It probably had to do with reading prices, etc., in the gift shop while feeling the motion. It also depends on how rough the seas are when you cruise.
We had a great time on the Inspiration.......we sailed her when she offered the 7 day out of Tampa. Get on board as soon as possible (we try to get to the port by 10:30 and are usually on the ship by noon). That way you can check out your room (even if they say it's not ready until 1pm, chances are it will be ready and you can put your carryon bags down), eat a great lunch and sit down by the pool and order the drink of the day! Then you can check out your dining room assignment and tour the ship before everyone else gets on. By that time (early afternoon), your luggage will probably be by your door so you can unpack and be totally settled in while some people are still getting on the ship! Some people don't get their luggage until after dinner, but I have always boarded early and have had my luggage early afternoon.
I don't know if you have sailed before but, in any case, my advice is go with the flow. As like any vacations, things can and will go wrong. Embarking might be a pain. Debarking can be awful, if you let it get to you. (my tip is to not rush that last day.......have everthing ready to go and then go have a nice breakfast in the dining room to avoid the lines at the buffet. Go back to your room and hang out until you absolutely have to go to your assigned area to wait for your luggage tag color to be called to leave the ship. Be aware that you might experience a long wait, and DON'T listen to everyone around you complaining........this is how you get off the ship and there's nothing you can do about it) You might have lines if you go to a tender port or if you go to the buffet at a peak time. Don't let the small things get to you and you WILL have a GREAT time!