What are the pros and cons of using dynamic array of records vs. TList<TMyRecord> in Delphi?

Question

This is a theoretical question intended to generate a look-up list of pros and cons of different data storage ways in Delphi.

Let's say we have a record:

type
  TMyRecord = record 
    X,Y,Z: Single; 
    IsValid: Boolean; 
  end;

Basic options of storing an array of such records are:

• array of TMyRecord;
• custom descendant of TList with getter/setter
• TList<TMyRecord>;

I'm specifically interested about #1 vs #3 comparison, how much is the difference between those, especially performance-wise.

Answer 1

TList<T> pros:

• Array doesn't have useful methods for adding/inserting/deleting/sorting/searching, TList does.
• TList has Notify method that could be overriden to perform some custom actions on item addition/deletion.

TList<T> cons:

• TList<T>[i] actually returns a copy of its element. So you can't write something like TList<TMyRec>[idx].SomeField := foo. Instead, you have to use temporary variable. Array obviously allows such expression. David Heffernan mentioned TList<T>.List which eliminates this drawback; however, it appeared only in XE3
• TList is an object which should be deleted at program finish when not needed.
• System.Generics.Collections unit could add plenty of binary size to a project that wasn't using System.Classes unit before.

For myself I wrote TRecordList<T> class which operates items as pointers (like classic TList does).