What kind of problems? I haven't heard of any in particular. Most of the reviews have been glowing. It is a new application and there is a small learning curve. iPhoto is still on the computers in the Application folder for those who prefer to use it and all photographs should still be in iPhoto.
In the app store where Yosemite is available for download, under “learn more” there are a number of comments by people who have had various problems. That’s what I was referring to. Based on these, I’m holding off upgrading to Yosemite until it seems more “trouble-free”. Any information you have would be appreciated.
The Missus claims 10.10.3 has made the iMac slower. I’m wondering if that was due to the initial transfer of photos, now that I think of it. I’ll have to ask her how it’s been more recently.
It most definitely HAS fixed the WiFi issues on my MacBook.