I was looking for an affordable set to replace my B20 alloy Meinl MCS set. I already owned an Istanbul 18" medium crash which suited me perfectly so Istanbul cymbals were a logical choice. I found some positive criticism on the XIST series to be an affordable, versatile and great sounding series of cymbal, and they have not disappointed. 
 
I use them for blues, funk, rock and reggae style drumming. 
 
Downsides: 
Rather thin alloy 
Very long sustain on the ride 
Ride bell is kind of dull 
 
Upsides: 
Decent price 
Very clean and reactive hi-hats 
Awesome crash 
Versatile 
Overall they seem well manufactured 
 
Overall I am really happy with the set. I am looking to upgrade by changing to a B20 alloy ride, probably Paiste 2002, for the shorter sustain and clear bell. In the meantime I have a moongel damper pad on the ride which shortens the sustain and that works well for me. All in all the set is great value for most styles of drumming.