After a very positive start with Yosemite installing easily I had a new pop-up about every hour telling me...
To run this web content you need to install the Java Runtime Environment
Which offers a link telling me I need Java 8u20, but there is no 8u20 at the link (or anywhere it seems) so I installed the latest update of that the 8u25. Java's own website scanned my iMac to say it was successfully installed and now I get the pop-up a little less frequently, about every 2 hours - Grrrr
I've not noticed an issue with anything I view online either, which seems odd
However - I have an iPad 1 (the original and it still works !!!) and when I went to upload some more photos for a couple's album design viewing not only did it not upload them, but it deleted every other photos on the iPad !!! Double Grrr
I've not even tried to resolve that one as yet
Dave