LaGuardia to Madison Square Garden. Planning to take the Q70-SBS bus to the E/F train. Google states total trip should take 1 hour, but I have read several websites that say 2+ hours. Any real world experience on how long it actually takes?

The difference in time would also depend on whether you are traveling on a weekday or weekend. I've used the M60 to get from LGA to Midtown (to the 125th 4/5 stop and then to Grabd Central) on a weekday morning and it has taken roughly an hour. However, i recently traveled the other direction during a weekday afternoon and it took twice that time due to traffic. Note that NYC buses and subways are often on modified schedules during the weekends and there can be delays due to the modified schedules.

1hour is properly time. But you had better hurry up.

2+ hours isn't completely impossible but that would be on a very bad day for both traffic and the subway, and might start the clock from the time you leave the plane.

Should be around an hour but depends on bus times

If no traffic then 25 minutes if traffice then upto 1 hour .

No more than 45 min

I think google is right