The drawback to having BIG-IP act as a full application proxy is the decrease in application performance.

This answer is incorrect because the full proxy model gives BIG-IP complete visibility and control over both connection legs, which is precisely what allows it to apply performance-boosting optimizations on behalf of both client and server.

BIG-IP's full proxy architecture is the enabler of its performance enhancements, not a drawback. By fully terminating and independently re-establishing both the client-side and server-side TCP connections, BIG-IP can apply TCP optimization, caching, compression, and SSL offloading that would be impossible in a simple pass-through or half-proxy model.