The wiki has the max level stats of the +10 equipment in parenthesis
http://harem-battle.club/wiki/Flower.../FKG:Equipment
The character specific equipment so far is all earrings, so they'll be better than normal earrings and give both ATK and DEF, but they give a lot less than the rings/bracelets (since they're still just earrings).
EDIT: Also, higher rarity equipment takes more exp to level and leveling equipment ends up getting expensive at higher levels, so that's something else to keep in mind.