Voci Armoniche make excellent reeds. It is easy to believe that because a reed is shaped from a narrow ribbon of steel with a blue edge, this makes it superior to the hand-finished reed that is cut from a wider piece of steel, and therefore does not have a blue edge. Maybe we should consider though, that both types of reed tongue are made from the same type of steel, certainly with Voci Armoniche reeds.
Perhaps, what makes many hand made reeds better is really the amount of time taken - to make, assemble and finish (and match the tonal quality of each reed in a given set) by hand - it's the subtle skill, precision and artisan techniques. However, I think we can sometimes overstate the excellence of the hand made reed. I have played plently of average accordions with hand made reeds. Indeed, some hand-finished reeds are very, very good. Many people believe musette accordions and hand-finished reeds make for a better tonal match.
The great reeds are more than ribbon steel cut in a certain shape. In 1956 when Giovanni Gola was establishing his new accordion model - what did he do? He contacted a great reed worker from his old employer, Dallape, and brought him to Hohner. Pietro Fillipazzi was given the task of working the reeds so the final result was the reeds responded to air pressure evenly across the range of notes. Also, the reeds were tuned with emery paper to give a more refined finish to the reeds.
Thermal bluing seems to be the hallmark of the Bluestar reed, and is a sign of the extra time and dedication taken in the making of the reed. This process might well have an effect on the overall sound of the reed. The fact that this artisan type reed is not made from nastrino appears to be irrelevant to the quality of the final product. It also serves as one example of an exceptional reed that does not conform to the normal rules of the hand crafted voice (i.e. with blue edge). It is not the only example!
There seems to be a trend these days to create hand-made-plus reeds. So many premium accordion manufacturers now use extra-special grade reeds in their top instruments - whether it's GHV reeds, Turbo reeds, Bluestar or double riveted etc. Some makers like Siwa & Figli deserve great credit for starting to bring elements of the reed making process back in-house. I visited their factory a couple of years ago and they were assembling proprietary reeds, and implementing new patented rivet-head technologies (again not conforming to the usual voci a mano rules). They were going back to the old Dallape way of producing their own special reeds. I also noticed the use of beautifully varnished stecca a biliardo reed blocks, which is very rare nowadays. This was more usually found in high quality Guerrini and Titano instruments of yesteryear.
If we are keen on the standard rules of thumb - such as 'hand made reeds have a blue edge near the rivet because they are cut from ribbon steel'. This works fine in most situations, but not all.
Well here's another useful general rule... Keep a close watch at what accordions the good Balkan musicians like to choose - they often make excellent choices!