+1 on both comments - completely agree.The turbo K4 would be the ultimate F power unit for performance. Unless the KV6 is turbocharged of course.
Sound wise, the KV6 has it all sown up. I love the slightly off beat low rpm exhaust note, which turns into a howl at high RPM.
We once had a 2.0 KV6 Rover 75. It sounded sublime even if not exactly a performance car. Many was the time I thought this would be a wonderful engine for the MGF.
MG Rover built a concept TF GT that was said would have a KV6 if it ever hit production (sadly, it never did), but the concept car itself "only" had the 160 VVC K16 fitted...