The flipside being that if I don't answer I'll be stupid, so...
Cools. The difference is half an f-stop. In practical terms, that like saying, "Oh, I'm forced to use 1/100sec instead of 1/160 second."
That's not even a doubling of exposure time. How much extra glass is there in the wider lens? 8mm more diameter.
The MAIN Q to ask then would become, "Which lens is significantly better in IQ at its widest - and for that matter, anywhere - stop?"
And that's for your purposes. OK, if you shoot stars at night AND the wider lens is just as good as the f/1.8, THEN MAYBE it's something to consider.
Am(
pining).