re: Viking Norseman Vortex Point Step Drill Bits

Interesting review to say the least LBD
Some additional comments.
Izzy Swan ... now he is a big boy that's for sure, or his side kick is a little girl.
He could possibly use his fist as a chuck!
Now
some constructive comments:-
1. Where do you get em?
Not at Trade tools, Total Tools or Sydney Tools.
2.  You mentioned to price but failed to make full disclosure , apart from indicating the pain the largest bit boring a hole in your hip pocket wallet would inflict.
3. You could use a a Simpson PT 27 to avoid falling swarf.
No doubt you have  one hidden away in your Melb Branch of Blackwoods! 
Not recommended on Possums BTW!
4. I guess JFK used one on his boat during his Navy days
5. Electricians step drill,  yep they would almost do the job, but beware in metal they are only recommended for enlarging orifices thinner or equal to the step section thickness.
6.  Other plastics and wood go for it Chip and Dale.
7. I have a 100mm beast for switchboards however don't be scaring  it to death with H or I beams.
Gutters, Colourbond and other thin (1 to 1.2 mm) sheet goods it similar to Viking Blood Eagling for them.