I'm a novice player and have initially used a plastic knick tenor. I'm less than 5 feet tall and have very small hands and was having difficulty in playing notes involving 3rd finger left hand, and all the right-hand fingering due to the stretch involved.
I chose this instrument after looking at and trying out several similar ones with the extra keys. I can now manage all the fingering easily with a good range of movement and without feeling the stretch in my hands.
The sound quality is excellent, the instrument is well-made, does not feel heavy to hold, and has a very pleasing streamlined, clean-cut appearance. The keys are of a flat design which I find makes them easier to use and adds a feeling of security of use.