There's a bit of distinction between a sleep status and a "freak-out" status. I had an idea in a thread a looong time ago that went something like this:

• Sleep duration is cut shorter
• Upon waking, you are slower for several seconds (drowsiness) and attack damage is reduced slightly (5%?)
• The sleep animation is fluid, not twitchy
• If the player is hit too hard or too frequent, they'll immediately wake up without the slow/attack penalties
• Sleep cannot be re-inflicted while you are asleep, and cannot be re-inflicted while you are drowsy

This makes sleep a bit of a hybrid of other statuses without taking away the thunder of those statuses. You use freeze to freeze things - you can re-position with your freeze weapon and strike again, or let thaw damage do its thing. Poison reduces attack AND defense, so it's a better debuff. You may get hit more while asleep in Lockdown, however a sleep mist bomb wouldn't be as effective as a freeze one, as a freeze one is continuously inflicted.