MTV3600D and MTV3700D are different in their HDD format and whether they support built-in Format HDD function. Therefore, I'd not recommend following the MTV3600D format procedure in that blog for use with MTV3700D.
I also used the Toshiba HDD 3TB BT01ABA300V and could format the hard disk to 3 TB and it seemed it was working well in the first instances. But after powered down for more than 10 minutes, the machine hang while power up again. For HDD of 1TB or less, it does not have such problem.
I have checked with Pixel Magic, they specify maximum 1 TB drive for MTV3700D.
KKLee: You may face unstable issue after upgrading firmware. I do have the same experience.