2nd Edition AD&D came out when just gotten into playing GURPS. For me it was too little to late compared to GURPS and I never ran it. However I remember what I liked and disliked about it when it initially came out.
THACO - thought it was way better than looking up to hit on a chart.
Thieves could customize their skills
Kits, thought they were a nice solution to customizing a character
Specialty Priests already did this in my last AD&D campaign because of the example in the Dragonlance hardback.
The loose leaf Monsters Manual
The DMG thought it was a inferior effort compared to the 1st Edition version.
The missing/renamed monsters and races 1/2 orcs, demons, devils.
The writing while it was clear and concise was boring as hell compared to 1st edition.
Later I bought some of the settings especially Birthright. I really enjoyed some of the 2nd edition Settings. I also bought the Paladin in Hell module simply because that picture was one of my favorite out of the old PHB. I bought the Night Below I liked the premise and presentation. I bought the 2nd edition version of Destiny of Kings as well as Return to Keep on the Borderlands. The Destiny of Kings remake didn't add much to the original. I did like the Return to the keep as a sequel. Should have bought the aniversary box but didn't as by then I was married and had to watch my spending.
My encounter with 2nd Edition AD&D has a sequel. Years later during a lull at a NERO LARP game I saw a bunch of 2nd edition AD&D books with the black cover. It was obvious that somebody was making a character. Looking things over I saw it looked like something from Champions or GURPS with a lot of point calculations and modifiers. When the owner got back I asked him about it. He showed me skills and powers and what he was doing.
I thought he was on crack.
All I could say was wow, AD&D was nothing like how I remembered. Now I am sure this attitude strikes you as ironic considering I like playing and refereeing Hero System and GURPS. However I played other points system too and those two are top of the line when it comes to point buy RPGs. Late 2nd edition AD&D with Skills and Powers was not top of the line. It seemed to me a very easily abused system. Indeed the player was telling me about some of the choice he made was simply the overwhelming optimal choice for class he was playing.
So that my impression of 2nd Edition AD&D.