It seems unreasonable to conclude that understanding of the phrase "how are you?" (or if you prefer "how do you feel?") in Chinese or any other language can be achieved without actually feeling or having felt something, and being able to convey that information (or consciously avoid conveying that information). Similarly, to an observer of a Thai room, me emitting สวัสดีค่ะ because I'd seen plenty of examples of that greeting being repeated in prose would apparently be a perfectly normal continuation, but when I tried that response in person, a Thai lady felt obliged - after she'd finished laughing - to explain that I obviously hadn't understood that selecting the ค่ะ suffix implies that I am a girl!

The question Searle actually asks is whether the actor understands, and as the actor is incapable of conveying how he feels or understanding that he is conveying a sentiment about how he supposedly feels, clearly he does not understand the relevant Chinese vocabulary even though he apparently uses it flawlessly (ergo P-zombies are possible). We can change that question to "the system" if you like, but I see no reason whatsoever to insist that a system involving a person and some books possesses subjective experience of feeling whatever sentiment the person chooses from a list, or that if I picked สวัสดีค่ะ in a Thai Room that would be because the system understood that "man with some books" was best identified as being of the female gender. The system is as unwitting as it is incorrect about the untruths it conveys.

The other problem with treating actors in the form of conscious organisms and inert books the actor blindly copies from as a single "system" capable of "understanding" independent from the actor is that it would appear to imply that also applies to everything else humans interact with. A caveman chucking rocks "understands" Newton's laws of gravitation perfectly because the rocks always abide by them!