My apologies for the late response, but I’ll be monitoring the forum for consistently now.
Line 240.3 is the third generation of Line 240 which was released back in 2007.
In general the Line 240.3, now have JET 5, which 5th Generation of the JET tweeter. There have been further refinement of the tweeters for sound quality and aesthetics. JET 5’s trim ring now has no screws.
The speakers cabinet also received a few aesthetic changes. The speaker grille covers are now magnetic, so there are no more mechanical attachments for a cleaner look. Components of the speaker chassis are now black for a more uniform look. lastly, the edges of the cabinet have a smaller radii for a sharper cleaner look.