regarding your comment, I am assuming however, that it is still best to choose the combination of instructions that result in the fewest clocks (as if the program were the only thread) within a given program, no?
For Each ctrl As Control In Me.Controls("pnlMainPanel").Controls
If ctrl.GetType Is GetType(System.Windows.Forms.Panel) Then
For Each subCtrl As Control In ctrl.Controls
If subCtrl.GetType Is GetType(System.Windows.Forms.TextBox) Then
If subCtrl.GetType Is ...