Reporting in, the settings from Mikey that Bryan shared:

verbose=1

kernels_per_reduction=48
threads=8
lut_size=15
sleep=0
cache_sieve=1
reduce_cpu=0
sieve_size=30

Are working better even for the 980 than what I had before.
The GTX 980 is now belting them out in under 12 mins with those settings! The GTX 1060 6GB can do 14 min, and GTX 1060 3GB is ~15 mins. These numbers are STOCK, no O/C going on, trying to keep the utility bills low as possible.
There maybe further tweaking to do to hit the best throughput for each card, but those times are from Mikey's settings above.
@FourOh - is your 980 beating 11:52 on your settings? If yes, I should look at tweaking my config files more...