Ive fished spinning reels for the past 25 years and prefer it, but started using baitcasters these past two years and definitely understand why fishermen use them.
The hardest thing i had to get used to was holding the rod while setting the hook. Im very used to holding a spinning rod and it does feels weird. And like someone else mentioned, on extremely windy days baitcasters can be a pita. I dont really throw anything over 5/8oz so spinning gear works fine for me.
I have been thinking about getting a swimbait combo, and if i do that will definitely be a baitcaster, thats one thing i wont use a spinning combo for.