Lets just say the story arc for Rand in TGS is, imo, amazing. The characters do seem a bit off, but I think Rand is the most true to Jordan's style.
The little Mat shows up in the book he comes off more as a Kelsier (if you've read Brandon Sanderson's Mistborn) type character. So he will probably seem the most off, and with this next book mostly centering on Mat and then Perin it might be the most jarring. It is possible with the extra work he did on this book (Sanderson did get an extra year to work on this section after all) Mat might seem more like Mat from the past.