It's the S300 and you can read all about it. But I'll share my thoughts.
I got to use it a couple times. Amazing! I can't wait to use this instead of the peri-bottle after I deliver. Most people think having a bidet is awkward and embarrassing, but after the sensitivities that come with pregnancy (tmi warning: hemorrhoids) and after (tmi again: perineal lacerations), the last thing I wanted to do was touch down there with abrasive tissue! The peri-bottle is great, in theory, but realistically it takes a long time to get warm water out of the faucet when you really have to go (or try using cold tap water HA!) and the bottle only holds a finite amount of water.
The downside is, it's a little pricey. Actually, Toto in general is on the high side. But they make excellent and efficient products and we've had the toilet itself for 2 years and never had to do a double flush! There are other brands of washlets at Costco and Home Depot, but I don't think it offers the same features and quality you get with Toto. We did benefit from a Holiday sale, but these can normally leave you $800 to $1200 in the hole. Admittedly with the steeper prices you get the functionality of a Washlet that will chlorinate your water and clean your toilet or even auto flush when you're done. How neat is that?!
I did not receive compensation for this, and wrote this completely on my own. Toto has no idea who I am, and probably doesn't care. I just really love my Washlet!