I only have a few k of several alt coins and i've missed out on a couple of possibly profitable trades because of the time it''s taken to send coins to cryptsy (doge took nearly 12 hours and didn't appear for about 200+ confirms recently although a few days ago deposits were only taking 6 or 7 confirms. So i'm wondering how many coins to people keep in their exchange accounts that they consider optimum in case of loss by them vs ease of trading?
It's always better to keep them yourself, but this depends on your circumstances if you want to keep them at cryptsy for ease of use. If the website goes down or is hacked there's a good chance you've lost them.