The b43 driver for the Broadcom 4331 chipset needs proprietary firmware in order to work. This is not included in Fedora (and many other distros) because it isn't open source. The process described at the link extracts the firmware from Broadcom's proprietary Windows driver using the fwcutter tool. Then you reload the b43 driver into the kernel using modprobe.
I used GNOME 3 on Fedora 19 on a different machine and it was okay. It was usable, but I prefer GNOME 2's interface and lower resource usage. Unity was pretty bad when I was using it in Ubuntu 13.10 and 12.04. It was bloated and crashed repeatedly. Now, KDE is pretty bloated too if you look at it from a resource usage perspective, but it's the one desktop environment where I can tolerate the bloat because it has tremendous configurability and looks great.
The Arch instructions could be better written IMHO. It's okay as long as nothing unexpected happens, but you really have to know what you're doing if it doesn't go according to the guide. It also doesn't account for using full disk encryption, which has different requirements, mainly with regards to partitioning and setting encrypt hooks in mkinitcpio. However, once you get Arch working, it is fantastic.
edit: I should add that Arch requires the same Broadcom firmware extraction method that Fedora does for the BCM4331 and other chipsets. This could make for a difficult install if you don't have an ethernet port, since the wireless won't work.