It's nice if you're not planning to do anything much during the day but if you're a pool person reserving a chair takes precedence over a leisurely breakfast in the DR.
That's a big problem since most people that normally use that pool will migrate to the other pools to escape their activities. They also tend to take over the aft lounge in the evenings.
We usually don't pack until the last minute and having our luggage with us to unpack as soon as we get to the cabin also means that there are less wrinkles to tend with. That, in addition to the fact that we don't have to be concerned about any items being taken.
As time goes by even the most dedicated passengers who prefer formal clothing come to realize it's so much easier not to pack the extra clothing just for those events, especially when a large majority doesn't bother.
If you feel the need to get involved in the Princess activities then by all means bring the white and gold clothing to blend in with all the other people.
Also, I think I've read posts that mentioned the 10% Elite discount is no longer applied if an item was put on sale. I swear I though that in the past it was applied no matter what the price was.