This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
Is there any performance difference on the bytecode generated using the same source on different compilers?
No, not really. In most JVMs, bytecode is further translated into machine code by a JIT or the HoptSpot engine (in Sun's JVMs.) These machine-code translators do further optimization, so the best performance generally comes from the most "typical" code. Most byte-compilers simply try to emit plain, ordinary code which is similar to what javac produces, to make the work of the JIT or HotSpot compiler easier.