The exhaust thread

Thinking of doing my first upgrade. Akra or Yoshi? The Yoshi after browsing is the RS3C but either titanium or carbon fibre and complete with SS Y pipe. The Akra has the Evo titanium and non Evo titanium and with headers or slip on, dunno if Y pipe is included.

What are the differences of the yoshi carbon fibre to the titanium?
The Akra Evo and non Evo?
Akra vs Yoshi?

Went with CF Yoshi myself ,,,,American made,,,,so if a spare is ever needed ,,,quick replacement and reasonable price,,,,sounds great,,,,