Just gonna say, it'd be much easier to rush through NG+ as you'll have access to the overpowered Personas you register in the Compendium, of course, you could just play on Very Easy and be in the 50's by the third dungeon, up to you. But to slightly correct Learli, items do NOT carry over, only maxed S. Link key items do, everything else is removed from your inventory.
There are no new level caps (always 99) or items (the unlocked ones in Daidara are available from the start though), and there's only one Persona that's only available in NG+ as long as you got the true ending in NG. However, there are some dialogue options that are technically only available in NG+ as you'd normally lack the required social stat level (usually Courage). Two of the S. Links (Sun and Strength) have 2 different NPCs/clubs associated with each (drama and band for Sun, basketball and soccer for Strength), the NPC you choose makes the storyline for the link different.