To make a long story short, if your about to order the base Rok EspressoGC machine and just want to make sure you have their weird size of single-wall/unpressurized basket for "true" espresso, the base unit already includes that alongside a double wall pressurized basket. Rok's listings could be more clear on that fact and I wound up wasting my money on this naked portafilter just to get what the base unit already included.
My reason for dropping this down to 3 stars though, is the poor quality on the plastic handles, which are also permanently attached to the metal portion. Portafilters I've ordered for my other machines have much better quality handles and can even be swapped out since they use a market standard screw size. For the price of 45-50 USD, the plastic handles on the official ROK portafilters are just not up to par.
The handle was loose on the first naked portafilter I received. To Rok's credit, they read my review for the base EspressoGC and sent me a new naked portafilter before I had a chance to directly ask them about it. This customer service is some of the best I have experienced from a company. If you have your heart set on a naked portafilter and order the official Rok version, they will have you covered if you get a defective one.
The replacement is MUCH better, but I've taken to the habit of holding these by their metal portion instead of the handle when knocking the puck out. I just do NOT trust the handles to last, especially when using them with a knock box.
I've had no issues with gushing or splattering that other reviewers have complained about with this naked portafilter, but I am experienced with how to use these properly. This splattering happens if the coffee bed isn't tamped down evenly. Ideally, you want a WDT/whisk to stir the beans and a good tamper to press it down. Unfortunately, the tools included with the EspressoGC machine aren't the best for this, but you can pull it off.
In my opinion, I would recommend investing in the pressure gauge instead. I'm finding that the naked portafilter isn't as important due to the manual nature of this machine, and the pressure gauge is allowing me to better determine and make adjustments to my grinders to work with the machine.
If you already own any 51mm baskets for other espresso machines, test them and see if they fit! Despite the information saying these official portafilters are 50'ish mm, most of my 51mm baskets fit both this and the original portafilter perfectly! Finding out my EspressoGC portafilters took my existing standard 51mm baskets, like my nice Normcore high extraction basket, immediately made my experience with the EspressoGC much better.
Just a few side notes about this portafilter:
*Both this and the original portafilter have a thinner edge at the top, which lets you get under the lip of the basket easier, and gives better leverage to pull out and swap baskets around. Despite my lack of appreciation for the plastic handles, this is actually a smartly designed feature that may not be on third party portafilters.
*The handle is probably plastic so the weight is less likely to pull the machine over when bumped. If you buy a third party portafilter, pay attention to the handle weight. The Espresso GC is hefty, but could still tip over and spill hot water on you.
*You can pull the retention wire out from inside the portafilter handles to make the baskets drop right out, or fit in tighter baskets.
*The naked portafilter has a thicker wire to make the basket a little harder to pull out than the original portafilter, while the original has a thinner wire for easier swapping between the two included baskets.
*The naked basket has a little bit of an inner edge that might interfere with deeper baskets fitting properly, though if they taper off toward the bottom they might still fit. You probably don't need a deep basket and should stick with the typical 16-18 gram capacity ones anyway; at full capacity, raising and pulling the arms down once yields about a 34 gram shot of coffee, so 18 gram baskets get you about a perfect 1 to 2 ratio.
