Leave my 750 alone!
I am in the same situation - my test is on Thursday. After going through the same type of anguish you seem to be experiencing I came to the conclusion that:
THE ONLY THING THAT MAKES A BIKE SENSIBLE IS THE RIDER - YOU!
I think choosing between a CB500 and a ST2 is like choosing between a Porsche and a Ferrari after passing your driving test. If you have a death wish then pretty much any bike is capable of delivering. Trying to convince yourself that a smaller bike makes you safer is probably tempting you not to accept responsibility for your actions.
Reasons for getting a smaller bike a primarily money: cheapre bike, cheaper insurance, cheaper repairs.
I personally will probably go for a 750SS or ST2, dependant upon test rides.
So, get what you want and:
- put photos of loved one on dash / inside crown of helmet with "daddy slow down" type comment
- choose a few bikes based upon usual criteria: fit, style, riding type...
- do several test rides
- make choice and get bike serviced
- drive carefully and practise
- continue learning through various post test training sessions
- remember that months 2-12 are most risky for new riders
Get the 750, just dont get mine!
Good luck.