Put me in the "Love it" camp -- I thought it was a refreshing take on the Righteous Bros. version, which felt dated to me. It is simple, tender, and raw. I also always thought it sounded kind of sexy -- a good candle-lit room song, with the sleepy distortion in the beginning and then the exploding climax. Bono's singing in this one -- very soulful.
Some of the guitar layering deeper in the mix reminds me of Miss Sarajevo a little.
I just got married a week ago, and this was the U2 song that we put on the wedding-favor mix CD. I couldn't bring myself to use With or Without You or All I Want Is You -- romantic songs, both of them, but they sort of send the wrong message.
Still, Unchained Melody fits in so well with the other U2 "love" songs of the period: Sweetest Thing, Luminous Times, Spanish Eyes, Hawkmoon ... all of those explorations on the pitfalls and curses of love, the bitterness and the burns, but also, ultimately, the beauty of love.
I once compiled most of the B-sides from Joshua Tree and Rattle and Hum, and called it "Stormy Kind of Love," with a big dark picture of The Edge on it. I still love that compilation.