My friend has the full termi, I have the full Akra...
Sound: Both sound good, Termi sounds better but is also significantly louder. I am sure that many would consider it too loud, although I think it sounds amazing.
Heat: I noticed my bike was significantly cooler with the Akra, and I have backed this up (to myself) when riding another friend's bike with the stock exhaust. As far as the Termi, I don't have personal experience but my friend with the Termi has stated that the under tail gets warm and the heat shield doesn't help too much. Likely Akra do to eliminating the cats and the positioning of the pipes.
Performance: My friend thinks my bike runs a little smoother with the Akra/upmap, but for me I can't tell. Both run better than stop and Termi has done a great job with their mapping compared to the mess that was my 1199.
Power: Both feel equal to me. I have seen Termi's dyno which shows the Termi making slightly more power, but we are hoping to dyno both of our bikes back-to-back. I don't think there is going to be a big difference.
Looks: I think both look terrible. Most have commented to me that they don't like the look of there Termi, and this board seems against it. However, I think it looks way better in person than it does in pictures and it really looks cool from behind. Looks are subjective, but the whale-.... Akra's aren't attractive to me.
Fit/Finish/Quality: To me this is the biggest different. I installed my Akra (with major help from a friend) and the quality of everything was amazing. I cannot speak for the Termi pipes, as my friend had his installed, but the quality of the accessories is rather poor.
The lower's don't match up underneath, their is visible differences in the carbon weave where they seem together on the lowers, there are area's where the flat clear coat is flaking off, and there are areas where it looks like the smushed the fiber together and loaded with epoxy in the mold. The lowers quality is really bad.
Each component (lowers, heat shield, exhaust parts) all have a different weave and a different sheen. The pipes that exit thru the lower are not even (the top right of one is protruding, the bottom let of the other) and the metal trim plate is slanted.
The Arka's quality on the other is amazing.
Conclusion - I don't have a ....... clue. For my OCD, I couldn't live with the Termi's visible lack of quality finishing, but I totally respect the sound and the MotoGP-esque packaging. That doesn't mean I don't like it, I really do, but for the price I expect more. Speaking of price, the Akra is just so stupidly priced that it makes you scratch your head.
Eitherways you are spending too much money for what you get