My gaming group all ended up swapping from exclusive sigmar to now exclusive 40k. The third edition rules proved too complex and irritating, the seasons changing how everything played for no reason, we all just missed 2nd ed and talks were had to go back. However we all rather move forward, so we climbed on board 40k and have been having a blast.
Having said that, we all keep tabs on model / army releases for sigmar and get excited for the lore and what's coming, so I think if the rules were more palatable we would probably all come back overnight.
For context, none of us are tournament players / competitive, purely beer and pretzel sigmar players