I’m an experienced player about five sessions into the Mirkwood campaign. I’m not sure if you’re planning on DMing or playing so I won’t add spoilers.
Positives
A very evocative setting with some really original roleplay concepts (I mean really original - like this is the setting where some of these tropes were first explored) pipe-smoking contests, spider haunted ruins, goblin holes, halfling feasts et al.
Some nifty mechanics that I enjoy a lot. Journeys, restrictions on long rests, flaws, cultural virtues, to name a few.
The martial characters are fun to play, even with the magic stripped out. Our party has a Dunedein wanderer, an elf rogue and a barding warrior. They feel balanced and powerful, even without magic in their party. 5e’s mechanics around healing and short rest powers really support this in a way that other systems struggle.
Cons
Shadow points can be a bit wearing at times. I think it is important that there be chances to remove these - through good deeds or particularly beautiful or peaceful locations. (Stannis Baratheon would be turning in his grave lol)
The warden and scholar classes are just poor. While the martials stand up against their PHB counterparts, these two equivalents for bards and I guess spell casters are worse in every way. They remove major class abilities without offering anything meaningful in exchange. Cubicle 7 should definitely consider revising them in future products. I’m really not a fan of making things a player should be able to attempt through the normal course of events into class abilities. For instance the ability to scout an enemy camp should not be a class ability, neither should trying to persuade an NPC to agree with you. Any PC that invests that effort into skills and roleplaying should be able to do these things. Unfortunately the scholar and warden classes are choc full of these types of abilities.
The adventure can seem quite linear. As best as I can tell but that may be just the stage we are at. The positives are definitely enough to make me want to keep playing in the campaign.
Overall summary 8/10. Be sensitive with shadow points, scrap scholar and warden and give players options and it is an awesome campaign system. You should definitely give it at least a try.