After playing under various VTTs, I chose Fantasy Grounds as the go-to, not only for the aesthetics, but the power of the culmination of preparation. Thanks to the assistance of a great community called the Fantasy Grounds College, I gained the knowledge through classes from very patient and knowledgable people (including the Founder of FGC himself, Laerun). Although FG can be daunting and an information-overload at first, once you have finally managed to get a grasp on it, games go faster than traditional TableTop and even faster and a more fullfilling experience than other VTTs.
One of the aspects that is true of most VTTs is the fact that much stuff has to be custom coded. Most would rather just play than sit for hours and prepare mundane tasks by hand and then be proud of a functional end-result. However, there are those that have such passion in the Fantasy Grounds community that they give their time and energy towards something greater.
Rob Twohy (Rob-2e) is one such individual; one of the old-school, crusty DMs that has not let the years diminish his passion of the hobby one bit. With drive beyond measure, he took on the task of providing this complete and officially accurate package of pre-coded spells, feats, traits and abilities that includes the FULL text and descriptions in the same format from the Official D&D Core Books; these details that are missing from the current, albeit functional, basic FG 5th Edition D&D Ruleset. Furthermore, such is Rob Twohy's commitment to a quality and up-to-date product, that he continues to maintain and revise these as Official D&D New Releases and Errata become available.
For most people, money is precious, but moreso their time. Once used, money can be earned again, whereas time cannot. So, would you rather pay $30 to yourself to burn the midnight oil and perform hours upon hours of tedious, detailed work? Probably not.
TL;DR Rob Twohy's Fantasy Grounds 5E Coding Package saves you and your players hours of tedious coding of Spells, Feats, Traits and Abilities so that your Fantasy Grounds experience is the best possible and it's also regularly revised when new Official Hardcovers and errata are released.