Shredding was cool in days of malmsteen,vai,gilbert and other 80's fellas ... Fast licks lasted just for a few seconds to enhance the melody, or to prove the technical ability of the guitarist , which is also cool IMHO.
Now what's the point of listening to senseless licks of 16th notes played over 300bpm for a straight 3 or 4 minutes (unless you plan to use it as an exercise) ?!