[{quoted}](name=Stark of Wrath,realm=NA,application-id=3ErqAdtq,discussion-id=6gQR5E1i,comment-id=0001,timestamp=2015-12-04T00:15:29.649+0000)
is more effective...
Ginzo's rage gives 15% bonus AD and 7.5% AP on hit. while gun blade offers 40AD and 80AP
That 6 AD and 6 AP adding to ginzo's rage.
BotRK offers 25 AD, which is only 3.75 additional to the rage blade on hit damage. However, you have to consider the 40% AS. Which I consider to be an 40% increase in over all DPS. Not to mention that the AS from rage blade also synergizes with the BotRK passive.
But to Gun blades credit. It's active should be more powerful. Since Gunblade only does 10% max health damage. (100 damage per 1000 health.) while Gun blade does 150 base + 40%AP (roughly 48 extra damage with both items.)
Conclusion: No Idea which is better. But the BotRK build should be better for DPS while the Gun Blade build would be better for assassinations. And of coarse you have to include the champion kit itself. Perhaps the Raw AP helps Jax since his abilities are hybrid. (Don't know about Xin though.)