I have the Hitachi CM753 Superscan and I must say this is one awesome monitor, the 715 is the lower end model, the 771 + 772 have higher refresh rates.
The 715 model does 115hz at 1024 by 768 and .22 dot pitch
My 753 does 120hz at 1024 by 768 and .22 dot pitch
So there is practically no difference only 5 HZ, I have an older model I got for $169.00 on Buy.coms error last year.
I would definately check the Hitachi's out, you won't be sorry.
They are Bright and vibrant monitors with awesome refresh rates to boot.
I have had mine over a year and still love it today.