Aww, poor 16VT ECU getting no love
The 16VT's Weber Marelli IAW P8 ECU is certainly getting on, but it's still extremely capable. From a performance point of view it's absolutely not worth going to the trouble and expense of swapping for aftermarket on anything but a true race car ...Or if your car has zero performance because it doesn't have an ECU in the first place!
The P8 can handle big power with ease, as proven by my own 16VT engine, currently making 440 bhp: It runs injectors with a flow rate of 760cc, a 3 bar MAP sensor and it daily-drives beautifully! Perfect idling and cold starting.
The WM ECU is very tunable. I can change pretty much everything useful; fuel/ign maps, map breakpoints, rev limits, boost control map - even things like battery voltage compensation and cranking fuel decay
One of the most important features is that it has a reasonable set of safety features; a proper boost limit map, air/coolant-based limits, knock detection. The only things it doesn't have are ALS, launch control or flat-shifting - although, I know that those have all been implemented in the past by people who are better programmers than I am!