Absolutely it's best practice to manually save frequently, but we all forget once in awhile or get carried away in a hot session ... so I also use Auto Save in addition to 'trying to remember' to save after every few edits. Auto Save has saved me several times after crashes and file corruptions. I really can't do without it. Which is why I agree with the OP, that Auto Save could use improvement.
I have it set for 15 changes. It only takes 1 or 2 seconds to save most projects. But when Auto Save keeps kicking off all the time during heavy editing ... it does interrupt my workflow and often blows up the key strokes or mouse strokes that I was launching into. After an hour of it, just seems like Auto Save is kind of fighting me. But still, got to have it. Love it / Hate it.