This is the most lean, tender part of the animal. There are also only two tenderloins per animal, which is why it's so coveted. The tenderloin is where we get high-end items such as filet mignon. Additionally, it's a key component of the T-Bone and porterhouse.
Buying the whole tenderloin means you can get the three cuts; the butt, the center-cut, and the tail. The butt end is usually suitable for carpaccio, as the eye can be quite large. Cutting a whole tenderloin into steaks of equal weight will yield proportionally very thin steaks from the butt end. The center-cut is suitable for portion-controlled steaks, as the diameter of the eye remains relatively consistent.
Note that PSMO stands for: Peeled, Side Muscle On (meaning that the fat is removed, but silver skin remains). You will need to cut this piece of beef into portions, but you will save some money by doing it.... and you get to play around with knives and feel like a butcher!