Still not sure what difference the age makes unless taken to extremes - immature teenagers misbehaving or old age ailmentgs preventing duties being carried out - both hopefully would be dealt with before the crew member made it to the aircraft.
Unless of course you want to spend the flight oggling the crew?
No one really knows how they would react in an emergency until the time comes. Better training probably = better outcome though - can't comments as not experienced either companys'.
Personally I am of the opinion that my safety on board is as much my responsibilty as the crew's, I know that excepting disabling injuries I WILL get out if there is any chance of it, hopefully taking my family/friends with me. Any assistance give will be greatfully received!
In a 12 hr flight I also want to choose my own entertainment - not an option on BA. I also want to be treated politely and as a human - including having a 'chat or 'joke' with someone who is happy and smiling.
On presentation I don't think theres much different althought VS uniform looks smarter in my eyes - not as fussy as BA pattern.