I've been using Yosemite with no problems. What problems have you been hearing about? It's at OS X.10.3 now and any issues you may have heard about have been handled.
I’ve read a lot of online reviews simply condemning Yosemite. They were older reviews and comments, so maybe the bugs are worked out. It is good to here that you are not having problems with it. There was a lot of initial criticism right down to the new Photo management replacing iPhoto.
Still have Rootpipe vulnerability as far as I know.
I have heard it loads notoriously slowly compared to Mavericks.
A lot of people don’t like the new user interface, don’t like the transparency. Some people don’t like the iOS look to all the controls, a step backward from Mavericks.
I’ve read some critics saying it freezes up regularly and they have to reboot their imac. I NEVER reboot my iMac. Once in a blue moon and it is usually due to some external software hanging up my internet. Usually forced close works in those cases.
It sounds like it is just not as polished as Mavericks. I am very happy with Mavericks, so the avalanche of criticism toward Yosemite makes me nervous.
I have heard it has gone back to smaller fonts you can’t enlarge. Maybe that is baseless, but those kinds of complaints make me hesitant to even try Yosemite.
It goes on from there. iOS is for CPUs that have that limitation. It is wrong of Apple to try to impose iOS on a personal computer that has the power and speed to run something better. I realize Yosemite is not iOS per se, but I don’t want my user interface to take a step backward and looking like a cell phone when there is no need for it with the speed and power of my iMac.
I will keep an ear to the ground but for now, I am afraid to jump to Yosemite.