going 16v only has its advantages to me if you have and amp that can take 16v and you subs will take the extra power
only bad thing is you have to charge your batts at 17 or whatever volts youll want to charge them at ........... but then you will have to run your car at 12v
there is a couple ways around this i think one of the easiest two are
running your stock alt then buying a 16v alt to run a dual alt setup and run the 16v to your system only
the second way i have seen work is to get a 16v alt and then get the kinetik 3 post 16v batts...... some people will strongly disagree with these batts but i have seen them work quite well for some local guys what you have to do is connect the batt like you normally would but then run you car off the 12v post side and your mids and highs amps off the 12v side but the trick is you have to connect all the 12v posts not just use one or two of the posts and call it good