As an option, I added the 0.3 mm refill to my order and that refill is superior to the 0.4 mm for me. It's cleaner and sharper, which stand to reason being a small size. Regardless, it was better to write with and going with the 0.3 mm barrel from the get go would have been the better choice.
One bonus if you are considering the Pentel Hybrid Technica is that they fit the Pentel Slicci perfectly, as in it is the exact same refill size an shape. An excellent option for those who want a wider Slicci barrel.
Overall, this is a solid pen, and if you are a fan of Pentel pens and inks you won't be disappointed.
(JetPens is a sponsor of The Pen Addict and this product was received at no charge.)