if ReadPropertyValue('Form1.Button1', 'width') > 1000 then
 ShowMessage('You are about to create a big button!');
function TForm1.ReadProp(r: TReader): string;
begin
 result := '';
 {Determine the value type of the property, read it with the appropriate method of TReader
 and convert it to string. Not all value types are implemented here but you get the idea.}
 case r.Value of
  vaInt8, vaInt16, vaInt32:
  result := IntToStr(r.ReadInteger);
  vaExtended:
  result := FloatToStr(r.ReadFloat);
  vaString:
  result := r.ReadString;
  else
  r.SkipValue; {Not implemented}
 end;
end;

procedure TForm1.ReadRes(PropPath: string; r: TReader);
var
 p: string;
begin
 {Skip the class name}
 r.ReadStr;
 {Construct the property path}
 if PropPath = '' then
  p := r.ReadStr
 else
  p := PropPath + '.' + r.ReadStr;
 {Read all properties and its values and fill them into the memo}
 while not r.EndOfList do
  Memo1.Lines.Add(p + '.' + r.ReadStr + ' = ' + ReadProp(r));
 {Skip over the end of the list of the properties of this component}
 r.CheckValue(vaNull);
 {Recursively read the properties of all sub-components}
 while not r.EndOfList do
 begin
  ReadRes(p, r);
  r.CheckValue(vaNull);
 end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
 strm: TResourceStream;
 Reader: TReader;
begin
 strm := TResourceStream.Create(HInstance, 'TForm1', RT_RCDATA);
 Reader := TReader.Create(strm, 1024);
 try
  Memo1.Clear;
  Reader.ReadSignature;
  ReadRes('', Reader);
 finally
  Reader.Free;
  strm.Free;
 end;
end;

Only one small problem.
r.SkipValue was protected (in D5) but I hacked that out with the following code:

type THackReader = class(TReader);
{ ... }
 THackReader(r).SkipValue;