I haven't tried it, but I'm not impressed.  Even the basic plan is extremely costly, and they provide very, very little information about it.  For $20/hr, I can get a local tutor and meet face-to-face one-on-one and she'll assign 'homework' as well.  Yeah, I have 1 particular local tutor in mind, but I haven't tried her yet.  Her presentation of what she provides is a -lot- better in a single page than theirs is for their entire website.

And note that $20/hr is the basic price on that site.  For the $40 and $60/hr lessons you get better teachers.  (It says so on their pricing page, with the $60 lessons getting you their 'Best quality Japanese lessons conducted by our most experienced teachers'.)

The trial lesson has a money back guarantee, though, so you could try it and see with no risk.