That reminds me to similar situation about KDE, when there was a big change - transition to KDE4. Many users left KDE and crossover to other DEs. But, hey, KDE is the most used DE today.
Anyway, one of the biggest complaint were very limited possibilities of editing and changing workspace in new Unity. Today is another story about that. You have various apps for personalizing Unity. The most used and the best, for me, is Unity Tweak Tool.
I don't remember if the app comes preinstalled or I added it later. Anyway, you can check in Ubuntu Software Center if the app is installed. If not, install it in one of ways we discussed in post about ways to install software.
As you can see, there are four menus and many submenus. Enter every submenu, see what it gets and tweak your Unity.
There is System Settings in Unity, too. But in there, you can change various aspects about System, Network, Printer, Security, User Accounts and so on. In System Settings, there is just one item, Appearance, where you can change wallpaper, icon size in Launcher, theme and some basic settings about launcher and workspace, just few.
Unity Tweak Tool offers you a wide range of options.
There are other similar apps for that purpose like gnome-tweak-tool, Ubuntu tweak, dconf-editor... And they have almost the same options like unity-tweak-tool, except dconf-editor. It has some additional options. You can try them, too.