This leads me to question why this information is required at all. I think the addition of 'microlight' or 'helicopter' to the callsign is worthwhile but, even then, the 'microlight' should only be the likes of Leia and not a microlight version e.g. a microlight Eurofox, as opposed to an LAA Eurofox. Why do ATC care a jot if it's a C172 seeking a zone transit or a C177 (I've even heard some smart-arse letting everyone know he was an RG.....Wow!!).
Likewise, who really cares where we've come from or where we're going? If it's for a transit I'm sure if I were ATC I'd just want to know where you are (so I can find you) and where you want to go (so I can see if there's something preventing that). If I were landing at an airfield then I'd be filling in their movements book, so why do I need to let everyone know I'm 'from a private strip 10 miles west of XXX' on the radio?
Some of the RT transmissions I've heard block the frequency for SO long with irrelevant nonsense about the precise type and mark of his aircraft, where he's been, what he's had for breakfast and his life goals. We should get rid of all that extraneous talking and just stick to the real basics, with the caveat of relevant information 'helicopter' (I know this is standard) being added. If ATC really need to know your type then I believe the default position should be that they ask, instead of us automatically telling......as I've heard people doing even when they're on a flight plan