[gray_-_wolf]

I've run into few issues:

1. Performance: lot of reflection and allocations, so not the fastest thing ever.

2. Case insensitivity: https://play.golang.org/p/LtwChO_tp0 this can be pretty unpleasant when it bites you

3. Unicode: It replaces invalid utf8 with unicode questions marks (dunno how exactly is the replacement character called) but does not provide any API to detect that it happened. So that can lead to silent corruption of the data.

[wlll]

3. in my mine makes it totally unusable, I didn't know that, glad I do now!

1. and 2. I could likely live with, but aren't great.