I have never been fond of the G35. It's not nearly as sporty as it promises to be, with an overly soft ride/handing and ladies-who-lunch interior ambience. Too steered towards luxury and not enough towards sport.
I would be shocked if a MTX Acura TL was anywhere near the price range Sigma's looking at.
While I like the Altima SE-R, it does not fill the shoes of the 1994 Maxima SE very effectively. It simply lacks the class, style, and near-luxury ambience and amenities the Maxima delivered (relative to its peers) while also deliverign the 4 Door Sports Car experience.