My LTR52246S takes about 21 seconds which is, in my opinion slightly shabby.
I have revealed that it doesn't matter what's the determined speed is or what the media characters are it still takes about 21 seconds.
Come to think about it, the writing process seems rather weird, at least based on my experience: It takes about 3 seconds to write the first 4% of the disc (Always 4%, no matter what size the media is) and that it taked about another 16 for the drive to speed up and for the red light to go on and only then will it start "real" writing procedure.
And by the way, it doesn't take too long to write 670MB Approx.: Less than three minutes.
Do i have a problem somewhere or are these descriptive actions seems normal to you?