Are you talking about Accord, or Civic? Si is Civic only, Sport-hatch now,
Coupe next year.
Mechanically, the Accord LX and EX(even DX) is the same, it just all
depends on what features you want or can afford.
V6 comes in only LX and EX, and a 6speed manual is only available
v6 EX Coupe which would make it the top performing Accord.