What a great discussion I fell upon. I have a DR-7 that I got new in 1970. It has the zero fret and adjustable bridge and a great booming sound. I have had other guitars come and go but I have never, ever considered letting go of my Sigma(I currently own a couple of Taylors I use for finger picking). This guitar is a war horse and has taken lots of abuse over the years but it remains in great shape.

A few years ago I had new tuners installed. After reading some of the comments here I might consider replacing the bridge saddle and nut with bone. Recently, I decided to get serious about playing slide and easily set up my Sigma for the job. The adjustable bridge made it easy to raise the strings and the zero fret allows for buzz free slide action at the top end of the fret board. I have gotten lots of comments about how great it sounds with slide. I think I will take this guitar to the grave with me.

Thanks