The shape is comfortable and the bulb sits nicely within the body. It stays in place comfortably over long periods thanks to the length of the neck. The only problem with the design is the manufacturing ridge that runs down the center of the toy. This may, for some individuals, be slightly uncomfortable during insertion.
As for size, the bulb is 1.5" in diameter at its widest point. The insertable length is 2.75". This size is good for intermediate to advanced users, but again, is probably too much for beginners. For beginning users who are looking for this type of toy, I would recommend the Love Pacifier Beginner, a smaller version of this toy.
This toy is fairly discreet while being worn, but it is relatively obvious what it is when not being worn. Therefore, I would not recommend packing this toy if you think your bags may be searched. Nor would I recommend going through a body scanner with this toy inserted. That would just be awkward.