Same story. I bought my Sigma in 1980. Played it with joy over the years. But didn't think it was so special, regarding the money I payed back then. So my kids played it (sitting on it and all). And than I brought it to a repairer who tuned it, refretted it, cleaned it, and fell in love with it. This guy ownes a Sigma himself and was delighted to be able to restore mine. Now I am very carefull with it. Since then I've been playing other guitars. My Sigma only got beaten by some of the more expensive Martin's!
Buy one and play it, you won't be dissapointed.