Dektol is a fantastic paper developer, imo. Now, I haven't experimented much with traditional chemistry, but it would not surprise me to hear somebody more experienced than myself say that Dektol is one of the most versatile developers out there. I experiment with alternative techniques often, and it seems something always calls for dektol. For instance, to tone a cyanotype, which is originally blue, back to black, you need dektol and tannic acid. If you look at the literature for Liquid Light, Dektol is the name they give when suggesting a developer. If you're thinking about making enlarged negatives for contact printing processes, most will recommend Arista OrthoLith in Dektol. Just a few examples off the top of my head. If you're more interested in experimenting within traditional printing processes, you may want to experiment with other developers for different tones, contrast, tonal range, etc. I would suggest buying The Darkroom Cookbook and mixing your own in that case. But if you think you'll be delving into alternative processes, stick with dektol. It'll come in handy more often than you can imagine.