Thanks for your comments and observations. Very helpful to me as I become older (in my case 72).
I'm an old dirt biker and 66. If you were staying on main roads and motorways the 650 would be my choice, although I have never ridden a Versys 650 the Suzuki v-Strom 650 feels top heavy and needs 50/50 tyres for dirt roads, even though it has a 19" front wheel where the Versys 650 only has a 17".
On Thursday I did two 70km stints on a four lane motorway and the VX300 did fine - although the motorway had a 100 kph speed limit and I have geared up my VX300, which has incidentally caused a "check engine" fault as apparently the ABS equipped VX300 does not like gearing changes.