Early 80's ES-335DOT models are very well-made. There's an '82 for sale near me that's very tempting.
I had a '71 ES-355 that was very bland in tone. Then again, I tried out a '74 ES-345 that seemed to really sing.
1970's ES guitars seem quite a bit different than any others. The specs were unique to those years. I believe center block became two separate blocks at either end of the body, one maple, the other mahogany. The neck tenon became very short, ending before the end of the fretboard (the main reason I'd be wary of 70's ESs). The pickups...may have changed a couple times too...I'm not too sure. The neck became 3-piece maple. Not all of these changes are absolutely negative (shortening the tenon is, IMO).