I did read on 'http://www.essentialaudio.com.au/index1.html' the following regarding the DX25TG05-04 :
A highly functional crossbreed of the MG & XT tweeter technologies. Extended high frequency response and good off-axis performance are achieved by using a specially treated lightweight diaphragm that utilises an oversized surround structure. A critically damped rear chamber and extra-strong 5-hole faceplate round out the attributes. Clarity, efficiency and extended frequency response up to 40KHz.
This will be the tweeter i'll use as a replacement.