Pot Mivv or M4 full system

Hi everyone, this is my first thread so bear with me

passed my test last august an bought my 2001 SV a few weeks later, absolutely love the bike but its got an original exhaust, i want something better sounding, i dont know of any work done to the engine but i do know its got a bmc filter
So basically iv narrowed it down to either a pot mivv GP with collector pipes or an M4 full system, which is best or does anyone know of any positives or negatives for either
(just out of interest the pot mivv is about £200 cheaper)