Assuming you have reasonable expectations, this product is 5-stars for what it offers.

You're getting a feature rich bidet toilet seat/lid with tank-heating.  Installation was straight forward.  Assuming you've done light plumbing work, you should have no problems setting it up to a standard elongated toilet.  Works great and has a handy remote that can be wall-mounted.

Since it's an add-on to   your existing toilet, it won't look as pretty as Toto's other full-featured offerings.  This means you'll have a T-fitting for the extra water hose, a power cord dangling out, and the general proportions will make the toilet look odd.  If you want the fully integrated look, Toto makes stand-alone toilets.  But if you're ok with function over form as a bolt-on, the C200 is a smart choice.