So true... the Voyager actually has a way better looking sword (shame he can barely hold it for crap but), and the hind leg transformation doesn't look as clever as the Voyager either. It looks like the lower legs both rotate 180 degrees to become the hind legs, which makes it little more than a "stand up and transform" quadruped (at least the legs do spin though). The Voyager actually is rather clever in its transformation -- the legs form the hindquarters, and the hind legs actually flip out from inside the lower legs (so they don't become kibble in robot mode).
Looking at the pics of Ultimate Predaking, things that look better than the Voyager (other than size) include:
+ Better paint apps
+ Better looking tail (but worse looking sword)
Both toys come with a pair of missile launchers - the Voyager's are the Hydra heads, and the Ultimate has those crossbow looking weapons. I don't think one is necessarily better or worse than the other... they're all missile launchers, so I guess it's a matter of personal taste if one prefers crossbows or hydra heads.I can't tell from the photo, but hopefully Ultimate Predaking can actually hold his sword properly.
But yeah... on closer examination I really don't feel the urge to get this toy when I already have the Voyager. I usually end up regret getting the bigger and dearer toys first, only to have smaller and cheaper versions come out later.
e.g.:
+ ROTF Megatron -- bought the Leader Class toy, then the Voyager came out. In hindsight I wish I'd skipped the Leader and gotten the Voyager instead.
+ Ultimate Optimus Prime -- bought this toy cos I wanted the trailer (certainly not for the wingaling Mega Pretender shell mode!), then about a year later they released the Deluxe version! (which I did get) Gah!