I think that the single most useful thing is the ability to cross-credit between the SEP, microlight, SLMG and ultimately glider ratings. This used to be possible, but was unilaterally removed by the CAA when they incorporated JAR-FCL.
But, for new PPLs, it also saves them from having to pay for expensive training in radio-nav, instrument flying, and suchlike frivolities that the majority will never use anyway.
Hardly anybody's going to do the 32hr syllabus in 32 hrs, but a lot will probably do it in 40-45, as opposed to the 60hrs or so that's the current average for a PPL(SEP).
I was chatting the other day to the BMAA's Doctor, who has been negotiating the reduction in medical standards from class 2 to the FCL150 standard used by microlight pilots. He told me that he's actually been receiving hate mail from AME's over the amount of revenue his negotiations have lost them. Now I'm all for people earning a living, but that lost revenue for the AMEs is staying in pilots pockets, or could even be spent on flying instead !
No it's not going to be earthshaking, but I think there's a point.
G