If you are using a Form Control, you can get the same property as ActiveX by using OLEFormat.Object property of the Shape Object. Better yet assign it in a variable declared as OptionButton to get the Intellisense kick in.
Dim opt As OptionButton
With Sheets("Sheet1") ' Try to be always explicit
Set opt = .Shapes("Option Button 1").OLEFormat.Object ' Form Control
Debug.Pring opt.Value ' returns 1 (true) or -4146 (false)
End With
But then again, you really don't need to know the value.
If you use Form Control, you associate a Macro or sub routine with it which is executed when it is selected. So you just need to set up a sub routine that identifies which button is clicked and then execute a corresponding action for it.
For example you have 2 Form Control Option Buttons.
Sub CheckOptions()
Select Case Application.Caller
Case "Option Button 1"
' Action for option button 1
Case "Option Button 2"
' Action for option button 2
End Select
End Sub
In above code, you have only one sub routine assigned to both option buttons.
Then you test which called the sub routine by checking Application.Caller.
This way, no need to check whether the option button value is true or false.