Just some note of my research on VB.net behavior.

Aggressive Inlining

• Unsupport recursion
• Not with Delegate

With Statement

• With statement make any value type become immutable except via instance method.
• With statement not get Dup optimize like Dim.

Meta Data

• Class = [Token][Field_1]…[Field_N]
• Array = [Token][Length][Index_1]…[Index_N]

ECT

• Any ByRef argument can bypass to other method ByRef directly.
• Structure is suitable for field and operator or static method, instance method should not be use, at lease it should use via interface of struct ref.
• Condition branch is very slow, use Do then If is faster then Do Until or Do While