I've had my page describing the Sight-Size method up for 15 years now. In transferring it and setting it up for this new iteration of my website, I thought the question might come up if I still use it or think the method is valuable. The answer is a definite yes.
Since learning the method and posting the page, I've created most of the paintings on my paintings page. My earlier work used the method with much more intensity. I still use the method presently whenever I do figure drawing or painting in the studio with a model. Even if I don't use the strings, mark the vantage point, or use the t-square, I'll still set myself up to stand in a manner that I can quickly flip my eyes back and forth between the figure and my drawing or painting. I've also done quite a bit of outdoor painting recently, and the skill and facility with flipping the eye from work to subject is invaluable.
So, the time invested has paid dividends for me, and I belive it can for anyone who is willing to do the same.