Needs more context. It's more mature for some things than others, like many young languages.

> how are compile times

Not Go, for sure, but not the worst either.

> how much of a priority are they

Getting them down is a high priority, but has taken some time to make a dent in. The last few releases have all posted speed ups, and "cargo check" in the last release helps. Incremental recompilation is coming, you can try its initial implementation on nightly today. There's a lot more to do, but users really want improvements, so it is and will continue to be actively worked on.