Yup, Kill bill is his peak, and the difference between one and two is very surprising and very deliberate. It feels like Tarantino is very aware of the line he is treading between reality and fantasy and he gracefully tap dances over those lines with purpose and intent, Kill Bill has many layers and on a superficial layer it ties all of his strengths together, genre film influences, 70's nods and killer dialogue. All together and used when appropriate.
It seems that his last two films, seem to have integrated all of those elements almost schizophrenically he's lost his touch in my opinion. Still fun movies, but his bag of tricks is thin, he used all of his trick up in kill bill and balanced them perfectly, now he needs to reinvent himself.
His identity was still formulating in Res Dogs, Pulp Fiction was his breakthrough but he's surpassed that, Jackie Brown seemed weak at the time but in retrospect is actually very refreshing and something he should look at before he does his next film.
Dusk to dawn? Seriously? True romance was good but dated itself quickly.