Solid glass will not get wet if the gelcote is up to grade. Even if it does absorb some water it will not effect the strength. Water absorbion with sold glass is rare to never.
Coring is stronger, littler and quieter. However you need to make sure all items piercing the glass is done correctly. Once coring gets wet it requires major work to repair.
I prefer a solid glass hull with all upper units such as decks and the wheel house fully cored. Fixing a core damage in these areas is simple. Hulls are a different story.