Need a little reassurance? :grin
1. You have a very good cabin location. Yes, it's a bit high, but at least it's midship.
2. My mom had a mid-ship cabin on the Emerald Deck. Her cabin hardly moved while ours on the aft was swaying, pitching and was incredibly noisy.
3. You've got "the patch". Those things work great!
4. If you've been through bad weather before, you should be fine. It seems to be the wind that is the main culprit, not the waves, IMO.
After all these fears, remember that the ship won't be taken into risky weather. No Capt. is going to risk an expensive ship if he wishes to remain a Capt. :grin
No, the Grand isn't "THAT" bad, but it is definitely worse than others, IMO. Nothing is worse than to be told everything is perfect and wonderful and then to get the shock of your life when it isn't. Go expecting the worst and I betcha you'll be VERY pleasantly surprised! 
