I've not noticed any difference in training. The difference and the reasons I prefer spayed females is no more (serious) fights, no more killing landscape plants, no more heat cycles in the middle of season. And as a hole a sweeter disposition. Oh yeah almost forgot, no more dog peter gnats!!
I've always had females, spayed after 2 heat cycles.
Spaying before a heat cycle is not typical in working dogs such as sled dogs, retrievers.
No peeing in the garden, on deck posts, etc. No problem if neighbors dog goes into heat.
However, from a statistical perspective, in the high drive sport of retriever field trials, males outperform females more than expected by chance.
From a statistical perspective, with no sex effect, about half the time the percentage of finalists would exceed the percentage entered, about half the time the percentage of finalists would be less than the percentage entered.
With females, the percentage finalists was consistently less than the percentage entered in the last five years of nationals:
Year NRC Entered Finalists NARC Entered Finalists
2021 35% 28% 40% 23%
2020 37% 36% Cancelled
2019 38% 28% 40% 27%
2018 37% 27% 36% 31%
2017 41% 31% 40% 29%
With about 35% of the entries females in the NRC, from a statistical perspective, the winner would be a female about 35% of the years if sex had no statistical effect. In the past 20 years, 5 females have been NRC winners which is 25%.
For the NARC, percent females entered is typically > 35%.
This year was similar at the National Retriever Championship.
30% entered were females with 28% as finalists.
Among the 2022 finalists, only 4 of 14 (28%) were females and the winner was a male.
In the past 10 years the winner of the National Amateur Retriever Championship
was a male dog 7 out of 10 years.
In the past 10 years the winner of the National Retriever Championship
was a male dog 9 out of 10 years.