I've said it before and I'll say it again. Nothing like a new set of strings. But which strings really pop? So I've cross examined all of my friends and came up with some interesting opinions. Now I am simple, I generally use D'addario strings. Why, because I get them for free! Come on, who can beat that but really I do love their consistency, method of color coding, and select gauges. But that opine generally is based on solid body guitars. So I needed more info for my acoustic guitars which I play less often. I have a Martin 12 string guitar and a Taylor 514 CE. Taylor supplied me with Elixir Strings. I loved them at first but then I tried D'addario Phosphor bronze. So I've used Phosphor/bronze for a few years now. Okay, I'll shut up and get to the data!
We found phosphor bronze to be very lively strings at the on set of application. The problem is longevity. I'd say these strings are lively for barely a week of infrequent use, moreover, an hour a day type of use. In comes the coated strings. To me, the coated strings sound better after a month than non coated strings. Most people I've spoke with had the same opinion.
To become a little more scientific about this new coating we need to look at the material used to coat the strings. Teflon has a great number of possible physicochemical modifications. At this point the laws of inhomogeneous polymeric materials are relatively unstudied and therefore the elastic properties of polymeric materials will differ based on orientation of their respective microsegments, and crystalline structures. To further add to the chaos; application techniques, material application, and relative strains (string tension, guitar scale) will add to variance that make this whole mess a wonder to study. Now for more simple terms.
The string manufacturers are rather quiet about the structures being used on guitar strings. At this point, we cannot say, String X uses a directional orientation polymer while String Y uses a random structure and therefore String X is better than String Y. Oh man! This type of information may never reach the String box label. Sadly, we must try each coated string and thus apply a non scientific approach to discerning the reason for better sound and tone. If different crystallite sizes are used, mixed sizes, random or selected orientation could yield better results. In regard to quality, musicians use their ears (subjective at best) and collective opinions to determine quality of tone brilliance. Shoot! For even more simple terms of selection.
Coated strings seem to sound brighter for a longer amount of time. Unfortunately this is qualitative and not quantitative data. I conclude that some coated strings will be better than others because different production processes are used. With the information available we can only hypothesize about coated string tone until someone like me or someone else lands some money (wishful thinking) to do a study. Some manufacturers will pay me to shut up while others will pay me to pontification the wonders of their coated process. For now, try them out and leave comments but save the arguments unless you have data.
IN conclusion, coated strings are nice but for me the price isn't worth the expense. Coatings will increase the brightness but this is dependent on the string. Elixir and Martin Coated strings have been the favorite amongst the Pros I know. I do think Coated strings have a viable place in performance but the ROI is still low at this time (2009). Indeed there are benefits to coatings: the coated strings will resist moisture, skin oils but these contaminates will transfer and adhere to the finger board. In conclusion we are only passing the buck in terms of the problem. Washing your hands might be a cheaper alternative. Maybe one of the engineers from one of the coated string manufacturers should get a white paper out there so we can all poke at it? Meanwhile, try them out and give us all a shout if you love them and let us know why?
All the best - Scott