Is fetching an object by String key be faster than a Key key? (GAE/J)

Thats pretty much the question. Are there any other concerns i sho开发者_JS百科uld be aware of?

No. Fetching by key is faster than querying, but it doesn't matter what form the key is in.

The only criteria in the documentation that I can find is on whether to use non-Key or Key is whether you have Entity Relations. If you do use Keys.