Of all of the '2.5' books I have to say I used this one the most. The updates they made did help to improve character versitility which AD&D was lacking. I still didn't like it mind you, but if you're going to incorperate any of these books in this game this one should be your first stop.
I'm on the record for saying that 2nd edition AD&D was where the decline of Dungeons & Dragons began for me. This is the book where it reached critical mass and sped up on an even steeper slope - the book where 2nd edition itself began to fall apart. It's woefully unbalanced and notoriously non-playtested, and adds almost nothing to the game except more clunkiness and unnecessary mechanical bits. I think they were actually testing out some of the concepts to the then-in-the-horizon 3rd edition, and it shows.
Half star for character points, which on their own are kind of a mess, but you could use them to customize the classes a little bit. I wouldn't recommend it overmuch, though.
Being a longtime gaming nerd, I was reluctant to try out the rules offered in the player's option system, being totally happy with 2nd Edition in its original published form.
I'm glad I was talked into trying it. The player's option system (Also including the Combat and Tactics, and Spells and Magic books) combine to essentially make AD&D 2.5 Ed.
The Player point system introduced in Skills and Powers, allows for incredible versatility in character generation. Two players, each making a fighter will end up with two vastly different characters despite being of the same class. The points also offer many options, for example: A player who doesn't quite qualify for that Ranger they wanted can 'approximate' the class by taking various skills and proficiencies to essentially make a Ranger, all without diminishing the uniqueness of the actual Ranger class.
The player points also offer a player in-game mulligans for those nasty save-or-die scenarios. A good system indeed.
The Combat and Tactics books examines not just the role of the fighter, but combat in general. The book offers a streamlined new combat system to replace the clunky combat system from the main books. Combat with the 'Phase' based initiative system is fast, exciting, and grounded. I introduced the system to a group of old-schoolers and they haven't looked back. Various combat options and specialties also give fighters such variety of skills without unbalancing the game, that no player has any more right to claim that fighters are boring old 'hack and slashers.'
Critical hit charts make those nasty hits exciting as a player waits to see if he's lost an arm! (Or taken an enemy's head)
The Spells and Magic book offer Mages and Priests a superior spell point system, which increases versatility immensely. The ability to amp up spells at the cost of using other spells, or vice-versa - to weaken them in order to allow others, gives a player with a wizard something to think about when organizing spells for the day. The 'Free spell' system also allows a wizard to save a spot for anything, but as double the cost of the usual 'fixed' spell option.
Overall I was impressed with the variations in the rules. 2.5 is my ideal of the game, (though I admit there's a lot in 1st Edition that has great appeal).
I've read a lot of criticism about the option systems, but it bears reminding that they are called 'OPTION' systems. You don't have to use it if you don't like it. I don't use all of the options, I use the ones that benefit the overall fun for everyone. Ultimately, you keep your game balanced, take what works, chuck the rest.
I've mentioned before that I settled on Second Edition D&D. I played 3rd refused to buy 3.5 edition books because edition3 didn't last long and then we were all expected to buy ALL NEW hardback books again... no too much money too soon. I bought all the 4th edition books and felt like ti mostly just dumbed the game down...so i went back to edition 2. This is a good addition to the core books...if the DM approves. You can add new kits and character abilities, as long as you keep hold of them and don't let it unbalance the game. I've used several things from it.
Not as awesome as I remember, but brought back some great memories. If you are playing second edition go ahead and get this book it does have a lot of cool ideas and alternate rules that are worth taking a look at.
I'm working on some game design writing, and I decided to pick this book up for some source material. I got a large-size paperback through an amazon.com bookseller for less than 20 dollars. It wasn't exactly inspiring, but it was a good buy for my project.