I love this Unearthed Arcana so much, especially for it’s simplicity and it’s shallow 5e breadth with immense room for growth, change, and ease of implementation. I love it so much I think I plan to use it in all my campaigns. While I don’t mind milestone experience systems, I love being able to award experience like additional treasure, and simple numbers like these are exactly what I need to be able to implement it with a range of scope for any and all adventures. The application of all three pillars of gameplay is fantastic. My one adjustment would be to reduce the amount of experience per monster, perhaps to 2 exp, 1 exp for large parties, and 5 for difficult encounters. Check it out!