I am on search for new nights for my 2nd Glock 19. I purchased TruGlo TFX PRO and love it the rear sight and the bright orange fiber front but IMHO I found the front tritium to be not big enough and not bright enough at night. The rears are great so... I look at XS Big iDOT but was told that the tritium is a standard size also, the white dot is just bigger. I am looking at Ameriglo which honestly looks exactly like the Truglo but uses the iDot system - meaning - one rear sight. Question: Are all tritium sights a standard size? Anybody have any experience with XS Big iDot and/or Ameriglo?