We have both... for most of the same reasons as everyone else. Try to not calve 1st calf heifers in the fall because it does pull them down alot. But the market here is a fair amount better for spring calves weaned and ready to go on grass, 4-550 lbs size... and yes, I much prefer they calve on clean early fall grass pastures. If the weather cooperates, then spring calving is great for the cows to go to grass late April/early May and breed back good when the bulls go in 1st of June... but we seem to get real hot fast with little spring weather... so sometimes some slower breeding back... they breed back real easy in Nov/Dec....
We also have had some "bad bull" problems... just this last group had 30-35 in there.... 6 all bred 6-7 months so calving in April.... the rest all open....20 or so, were younger cows... younger cows got put in with 2 bulls and hope to get them caught in 30 days, for Dec calves, 5 old(er) cows got culled and were in pretty decent shape so prices were okay. But we lost basically a year through no fault of the cows... Something happened to bull, but everything seemed to be working fine so did not break the penis..... He got shipped with the cows. If there had been a bunch 6-7 months then some shorter, could have figured he got hurt then recovered... but 6-7 months and NOTHING. These are all checked ultrasound now and the vet is good....bull was good when he went in.... so we took it on the chin and will try to buy a few more with calves by side or ready to calve in the next month or so....to build back up the spring numbers. Easier to calve the spring group as they are all at the barn lots, but again, like everyone else, mud and cold and then we sometimes get these surprise snow storms or cold rain/ice and do not have inside facilities to put them when it's bad.... I'd like to calve in May/early June and then put them out and put bulls in July/Aug... wean calves in Jan, get bunk broke and on silage/feed, and then sell in Mar... 5 wt calves are highest prices overall.... but we are in hay and that is too much to do on any given day.
Never a perfect time and when you think you have it all worked out, you get thrown a curve ball like with our bull going bad....