Get the 15". You'll find it to be easier to handle. The geometry of the bike will give you the dh prowess you need, no matter which bike you get.
The TT length is noted at 22.25 on the 15" so it will be similar to the Giant. But the HA will be different than the Giant and that's where the extra stability will come into play.
What kind of parts are you specc'ing? I notice that Ellsworth upped the fork travel amount to 150mm, so you have lots of options there.
Congrats on your new purchase by the way! And welcome!
The TT length is noted at 22.25 on the 15" so it will be similar to the Giant. But the HA will be different than the Giant and that's where the extra stability will come into play.
What kind of parts are you specc'ing? I notice that Ellsworth upped the fork travel amount to 150mm, so you have lots of options there.
Congrats on your new purchase by the way! And welcome!