I have a 70 druid and shaman.
My conclusion, solo leveling -> Druid = Easy mode, especially if you are feral.
You are NOT gear dependent. You dont need a good weapon to do good dps. (at least not while leveling up).
With stealth, you can selectively pick and choose who/wat to kill when questing and skip the time wasting trash. Never had to worry about getting another good item just to keep up the dps level.
Enhancement shaman (I leveled to 70 as Enh) is fun. Little downtime, but killing speed/efficiency varies as I level up. Whenever I get a new buff (e.g. WF), or a new weapon, Whoa, fun. A few levels later... so slow...
Also.. I tend to be ganked a lot when playing shamans. Simply because we don't have any escape mechanisms. While when I was on my druid, most of the time they leave me alone (I guess most pple know it's hard, they can run away real fast).