Yup, don't forget the fact that you'll end up doing pooling, free lists and the exact same performance tricks you'd need to do if you managed memory explicitly.

Yup, don't forget the fact that you'll end up doing pooling, free lists and the exact same performance tricks you'd need to do if you managed memory explicitly. You're adding a ton of incidental complexity for a benefit that you can't take advantage of(programmer productivity) because you don't have the necessary resources to make it happen(large swaths of memory and > 50ms response times).