Neverwinter doesn't stray far from Cryptic's recent offerings. If you have played STO you will recognize many of its features re-skinned and re-purposed in Neverwinter. If you can tolerate its glaring technical issues and questionable design decisions, Neverwinter can provide some short term fun, and might be worth a download.
In terms of value, this free-to-play offering can be seen as either a fantastic bargain or as a heavily monetized rip-off. If you don't want to spend money, you don't have to. All of the game's content is available to free players. However, basic game elements such as inventory bags, character slots, and other features all require real money to unlock, and even by cash shop standards they are expensive. On top of that, there is the annoying (to me anyway) feature present in all of Cryptic's games. Loot boxes drop ubiquitously, and can only be opened with keys purchased from the cash shop. At a $1.25 a clip, these keys are expensive, and a typical character will accumulate literally hundreds of boxes on their way to the level cap. For the most part, these boxes don't contain anything worthwhile. They are the MMO equivalent of scratch-off lottery tickets. This feature is the primary turn-off for Cryptic games for me, and the one that makes it unlikely that I will play their games in the future.
In addition, key features of the game are frustratingly broken. The looking for group feature doesn't work properly. After waiting in a queue players will be ported into an instance, only to discover that it has already been cleared. As daily dungeon quests are one of the primary ways to earn astral diamonds, Neverwinters in-game currency, the lack of this feature is particularly noticeable.
For all of its flaws, Neverwinter is fun for a little while. It doesn't have much depth or variety, and didn't hold my interest for long. But for casual players looking for a free diversion, it has some value.