yes there is a difference
normal unleaded has around 95 octane then you get 98 and then you can get 100 then its racing fuel at 104
some have an ethanol blend
if you want to know what petrol for youre bike just go the 95
its not a super tuned engine (unless youve spent big bucks on engine work)
edit
i just remembered a dyno comp i was in ,i overboosted the octane did a run and got my reading
drove to servo put some normal unleaded ontop of what i had in the tank
did another run and gained 4 kw with lower octane
the reason was to much octane will foul the plugs
I have used high octane and normal petrol and didn't find a difference.. But in saying that I normally got the octane stuff because it's normally less than a dollar difference between buying 5 litres or either..