Guys that can go ape **** on arpeggios at 1000 mph are a dime a dozen. There is so much useful stuff you could be learning that will put the fastest players to shame. A cat that can put lines together puts the fastest speed demon to shame! :chairfall I would spend my time trying to think melodically! Speed will come by itself overtime.
If you practice everyday you should have enough dexterity for a reasonable amount of speed! People who don't have to think about what they're playing are always faster than those who have to think about it! Arpeggios and modes are mindless. You just play patterns and bend the **** outta strings! :chairfall Putting together real melodic ideas are more challenging and rewarding!
No sooner than I finished the last paragraph somebody most likely is prepared to start ragging on melodic playing! Look! Playing melodically doesn't mean you have to sound like you're playing "Moon River" or friggin "Alphie" damn it! There all sorts of melodic methods that one can use that are radical as hell! Let's see there are automatic destinations, pointalism, aleatoric methodologies and the list goes on! You can create some lines that are out of this friggin world! You will have your "fast" friend calling you an alien! :chairfall Your friend will be stuck playing really fast in some boring, stale ass mode. You on the other hand will be all over the place! Exploring remote key centers and playing all sorts of crazy substitutions! Now that's what you call doing your homework!
I would rather be equiped to figure out what to play rather than how fast! Just concentrating on speed for speed's sake is like going to the gym to do squats everyday and walking out with a big beer gut!