TF2 went to shit as soon as it became F2P, and it was pretty bad before that too.
Vanilla TF2 will always be better, hats and shit ruin the experience of TF2 completely.
Try deleting the clientregistry.blob file found in USERFOLDER/Library/Application Support/Steam, this should force steam to reupdate. If this didn't work, delete everything in that Steam folder except for the Steamapps folder.