I just saw this version of "Tennessee Waltz" by Bonnie Raitt and Norah Jones on my FaceBook feed. I thought it was beautiful. It brought up some issues that I run into from time to time with students. Namely, "Why don't you teach bottleneck slide?"
I consider bottleneck slide to be a specialty and I'm not particularly interested enough in it to do the work that it would take to solve the 3 major problems I see with it:
1) It's impossible to play any kind of sophisticated chords with a slide. This problem is only solvable if you develop some kind of hybrid technique where you take the slide off to chord and put it back on to solo. Awkward.
2) I cannot find the words to describe the horrible, fingernails-on-a-chalkboard sound of a slide scraping a guitar string. Why anyone would find this an attractive sound is completely beyond me, but there's no accounting for taste.
3) Intonation is a HUGE issue with slide players. Almost every slide player I've ever heard plays out of tune. My first exposure to bottleneck slide playing as a young teenager was Johnny Winter. Even at an age where I didn't know squat I could tell he was mostly out of tune, and the scraping sound drove me bonkers. I could name any number of famous slide players and the issue is always the same.
In my experience (granted, I am not a knowledgeable slide player aficionado) there are only 2 people I've ever heard who made me wish I could play bottleneck slide guitar. First and foremost is Bonnie Raitt - thus the relevance of the YouTube video referenced above. Her pitch control is flawless. She is always spot-on. When sliding up to a note she always stops the slide on pitch. I hear no string-scraping sound when she plays. I love her slide playing. I also love her singing. Her singing and slide playing are images of each other. She plays like she sings and sings like she plays. Both are very soulful and beautiful - but there's no accounting for taste.
Secondly, Derek Trucks. I saw Derek Trucks years ago when he was about 19 years old opening for John Scofield. I had never heard of him. I was very impressed. His pitch control was very, very good. He had a pretty smooth move where he slipped the slide on and off his finger from the watch pocket of his jeans. If you weren't watching closely it was like the slide appeared out of nowhere. He sat in with Scofield's band (which included Steve Swallow on bass) at the end of the show and acquitted himself adequatly in a non-diatonic context. I could hear just a little scraping when he used the slide on the 6th and 5th strings.
If I were to seriously attempt to play bottleneck slide I would first work on eliminating the scraping sound and then devote most of my time to gaining complete control of pitch. But there's no accounting for taste.