If you have good generational GC (with relocation), then creating and destroying short-lived objects should be almost free?
In practice, you will be re-using the same areas of memory.
In practice, you will be re-using the same areas of memory.
In this case, I also doubt it would make a difference by itself, but I haven't looked at all of the source, so I just mentioned it as something to maybe watch out for. Also, every bit of GC you can super easily avoid "buys" you room for GC that would make the code more complicated to avoid. Waste not, want not :)
See the comment by kibwen (https://news.ycombinator.com/item?id=18551218) for some good pointers to more concepts.