I got a friend Big Boy under the promise that he would write a review. Here's what he had to say:

Use
The Big Boy is intended to be used as a prostate and perineum stimulator. When inserted with the vibrator positioned under the perineum, the toy is curved to press into the prostate. A battery is included and already installed in the vibrator (a paper tab must be removed before use). I have not been able to insert the Big Boy completely in the intended direction because of the length of the insertable portion and the angle when inserted. However, the Big Boy is easy to insert when facing in the opposite direction while still providing strong vibration and anal stimulation.

Material/Texture
The Big Boy is made of pure silicone. The toy has a matte texture and is firm, providing moderate flexibility at the elbow between the insertable part and perineum stimulator. To my nose, there was almost no odor when opening the package initially. After cleaning, it only retains a hint of any perfumes used in the cleaning products with no chemical-y odors remaining.

Design/Shape/Size
As a prostate massager, the Big Boy is shaped to apply pressure to the prostate when inserted. The insertable portion of the Big Boy consists of three lobes increasing in diameter from 3/4" to 1 3/4" with the first lobe tapered to ease insertion. Being only moderately experienced with anal toys, the Big Boy is somewhat challenging to insert completely because of the girth. However, the shape of the lobes and the strong vibration help ease insertion.

Function/Performance/Controls
The bullet vibe in the Big Boy is a simple, one-speed unit. It is reasonably quiet while providing decent vibrations that can be felt throughout the toy, although it is noticeably stronger at the base where the vibrator is located.

Care and Maintenance
The Big Boy is constructed completely from silicone, so maintenance is very easy. I covered the Big Boy with a condom before use and only used a water-based lubricant, making clean-up a breeze. A quick wipe with a toy cleaner or a wash and rinse is all that is required. The vibrator is waterproof, so there is no risk of damaging it while rinsing.