Bump. I have the exact same question about these exact two toilet models. ckknh can you share your ultimate decision/experience?

We decided on the 1.0 gpf model. We talked directly with the Toto rep, who said that the
1.0 model used new technology, and would perform better than the 1.28 gpf model. it has worked flawlessly, and we have never had a clogging issue. Highly recommended.

Thank you! How do you like the 300E?

We loooooove the washlet! We'd used it in Montreal when staying in a hotel, and decided to add it to our bathroom remodel. The only snag that we've had is that the pre wash sensor is so sensitive that it would go off when someone entered the bathroom (our toilet is not in a separate room). We solved the problem by taking off the plastic sensor cover on the washlet, and putting a small piece of cut to size card stock over the hole, then putting the cover back on. That decreased the sensitivity sufficiently to make it work only when someone lifts the lid or sits down.

We like the toilet and washlet so much that we're replacing our other 3 toilets, and adding another washlet.