I can vaguely remember being "put off" by those plastic parts when I was deciding whether to buy mine,glad I did of course and now the plastic sight...
I was thinking of buying one of the cheap ones but after looking closely at the pictures I went for the £40 Warren Edwards one for my TX and might go...
Have tried a couple and to be honest I was not happy with the fit and finish so returned them for refunds. I would buy a Warren Edwards one if I were...