Watch out if you do, a lot of people at work upgrading to it from Mavericks are having trouble with their Wi-fi connection dropping in and out, which is a pretty widespread complaint by the looks of it. Apparently as a new install it's fine, but the upgrade is a gamble.
I use Yosemite all the time, I like it as an upgrade from Mavericks, I feel things are snappier, including safari which is a plus for me. If you are unsure on whether you want to make the plunge, you can always partition off some of your free hard drive space and do an install to there so you can test it before you change over - That way you have all your files and stuff still backed up. There are some people who have experienced problems as the apple forums are full of people with problems - but aren't they always?
I have had no problems, and all the apps I use regularly (photoshop etc etc) have had no problem with the upgrade.
If you want to partition the drive to try it first, you may need to convert it to an ISO and burn it first before it will let you install (you can also use this method for a fresh install), if so, you can find instructions on the blog on the site on my signature (cv pc repair) I wrote an article on this topic a week or so ago.
I am a bit of an apple fanboy haha, I love all the imacs, the 5k is over the top for most everyday use - sure, but if you can afford it, it's great. It's more for video editing bet it is crystal clear, but probably real power hungry ;-)
The only major difference I have found is the search option (spotlight). It now searches wiki pages, and other internet sites, has a different looking window, and overall has a different feel to it.
I am a bit of an apple fanboy haha, I love all the imacs, the 5k is over the top for most everyday use - sure, but if you can afford it, it's great. It's more for video editing bet it is crystal clear, but probably real power hungry ;-)