Exciting "extras" that would push it over the top for me are things like
- electric heads
- bluetooth
- watermaker that actually works
- enough solar to run a properly sized fridge without running the engine all day
- countertop icemaker!
- a dinghy boarding ladder, something everyone always wishes they had, but never seems to get.
- Decent, modern ground tackle. Not some 30 yr old CQR with 75 ft of undersized chain.

These are exceptional items that would make a charter boat more attractive for me. The list is different if we are talking about required personal cruising equipment, but this is the sizzle that would sell me on a charter boat.