I have used blends for years. They are wonderful because they fade less, they are strong and frequently their colors are more vibrant than pure cotton.
I had no idea that my 65 percent cotton, 35 percent polyester was offensive to "real quilters" until I joined quilt guilds. Despite their horror, I continue to use whatever fits into the quilt I'm making and sometimes I use 100 percent cotton and blends in the same quilt.
To tell the truth, I think some quilters have what I call a Hyacinth Bucket complex about fabric! Use those blends! They will be wonderful.
FroggyinTexas
P.S. Hyacinth Bucket is a character on one of the British comedies broadcast by PBS stations. The program is called "Keeping Up Appearances."