From my unresearched perspective, the difference is that Musk (admittedly) is pursuing crazy ventures because he's passionate about them -- and oftentimes for no other reason. He apparently originally expected that SpaceX would be broke by the time he had managed to get to Mars.

Branson seems to be deeply rooted in a business-first approach to creative innovation. "Yeah, we'll do it, but if the market accepts it."

Yes and no. (Mainly no)

It is unquestionable that Rb has pursued many different avenues despite there being little to no obvious commercial benefit. I do concede that you could argue it is just in the name of building his own profile, but for example did you know he started a charity aged 17, the Student advisory centre where he used to personally give advice over the phone (apparently still running) and that he started mates condoms[1] (UK based). He is also the one behind the eldars[2] (http://www.theelders.org/) and countless other projects including helping african communities establish sustainable business (to name just one).

1: http://www.mates.co.uk/mates-expert/history/ 2: http://www.theelders.org/about

So... brash, impulsive, and often luck-based ambition vs. careful, calculating ambition.

I'm not sure if we really need to value one over the other. The fact that Musk threw caution to the wind I do not believe is really a virtue - it just weaves a more interesting tale after the fact.

+ Possibly the worst train company in existence

Must say I agree with ErrantX on this one, by far the best trains I have used (in the UK).

I'm confused. Virgin has trains?

In the UK, yes, they operate a couple of rail franchises.

Personally I've always found them far and away the best company - but they have the misfortune of running "cross country" routes, which go through every bottleneck in our rail system :D

WCML is an abomination of a service.

Toilets frequently out of order. Carriages with toilets reeking of urine. Reservations downloaded to the train maybe one time in 5. Empty first class carriages while standard contains double the number of people. Attempting to stop people with open walk-on tickets from getting on valid trains. etc. etc.

Maybe it's just my (and everyone I know's) bad luck that these things happen every single time I (we) use them.

No, fair cop, I've only ever used Virgin Cross Country, never the WCML. So obviously I've only seen one half of things.

To be wholly fair, I have rarely enough used Virgin Cross Country that I can't bring to mind any explicit badness therein.