The Warchal Amber strings have a unique sound quality, nothing like what I've had till now on my high quality old Italian violin (and I tried so many). I needed a lasting, yet powerful and great sounding strings to use while working as a concertmaster and a solist. 
 
Time: 
They settle fully on the instrument in a few quick days. It's important to wait for the strings to stretch, that's when the clarity of the sound really comes. 
 
Sound / ease of playing: 
These have none of the metallic or artificial sound qualities many other models have. Once settled, they sound like a human voice- very warm, yet powerful. No need to put any bow pressure. They respond especially well to high bow tension and low pressure = great, singing sound. 
 
Quality of materials: 
My hands are very sweaty and acidic, so unfortunately no strings last too long with me. But I had no problems for one month of intense playing and practicing with these (a month is a long time for me). The A string only recently started unwinding in the 3rd position (a problematic string with so many models), and D string tends to stretch quite a bit after a while, the gaps between the windings getting more visible. But even in this condition, the sound quality didn't change at all. 
I always used a dry microfiber cloth to clean the strings with very good results (without alcohol). 
 
The E string has been manufactured in a very interesting fashion (curled bow area that stretches into flatness), but I didn't try it yet. 
 
Summary: 
Give this strings a go. After having tried dozens of models of the other big brands, I am very pleased with these. You could be surprised.