So, I've been using this STP pretty consistently for about 4 months, and I have to say that I love it. It is light and folds up easily which makes carrying it discreetly in a packet very easy. It sits nicely against me when I'm using it to pee. The lip along the inside of the cup that prevents spillage does exactly what it's supposed to do and is not super pronounced which allows for a much more comfortable experience.

Because the entire piece is hollow there is less of a need for the user to control their own flow which is great. A few of the other STPs I've used have just had a small opening down the shaft which means you, the pee-er, have to maintain a specific and consistent level of peeing in order not to spill over. Sometimes you just have to go, and in those moments it's difficult to maintain a steady slower flow so not needing to is great, which is a huge plus for this STP in my book.

It is also very easy to clean. Rinse after every use. Wash with soap and water once a day if you've used it.

Like the description says you do need to press the bottom of the balls to your body and create a seal in order to use it successfully. However, the description also says that you need to pinch near the head to open the urethra (read: pee hole) and that is just not true in my experience. The hole is plenty big enough just as it is and does to need any manipulation other than to aim. I've found it easier to use if you lean forward or shift your hips out and down a little just to get the positioning right but this will change from person to person and body to body. It will take some practice to make sure you've got it right if you've never used one before, and I would highly recommend using it in the shower a few times just to make sure you know how to hold it and how to stand - this is just to help you avoid pee in or on your pants.

All of that said, I think listing this as a packer is a bit misleading. While the totally hollow design is great for the STP aspect, it does also mean that it folds rather than beds making the shape a bit awkward in underwear. It is also a pretty firm material which means it's not super comfortable to keep in your pants without it pressing or rubbing.