I don't think I would spend $800 for 1-2 hp, which is all my buddy got with is Akra dual slip-ons. The HMFs sound great! I only wish I could hear a HMF big bird, MSF and gang say they sound even better than the duals.
I opted to spend a little more, $970 and gain 10-13 hp, louder sound, and the high mount look.
You can get the aluminum for $902 shipped in the US from Silvio, I spend extra to have the cans powdercoated black.
Also, you are not FORCED to buy a PC3 with the HMFs. I have been driving mine on the stock ECU, and it is running just fine. You are however forced to buy PAIR block-off plates. Around 50 bucks from Tom at Veltune.
So, actually for around $1050 you have have what 4 times the hp, and louder exhaust. Then spring for the PC3 when/if you want.
Now I just have to dyno it to find out how much they REALLY gave me.