I was thinking of purchasing a SU800 to IR remote trigger my SB800 and SB600. Now I read about instead of using a SU800, you can also use another SB800 as master, attached to the hotshoe, with it powered down to -3.0 to avoid direct flash from it. Question is, SU800's range will be an advantage over SB800's? Cause for an extra of $60-$70, I did rather get another SB800. Thanks in advance for any opinion.