I've not heard anything too negative about the XtraKit Swift
Actually, I didn't hear much about that kit at all one way or the other. It entered the market rather quietly and with little fanfare.
I wonder if having someone other than MPM do the tooling and molding had something to do with the quiet reception. As I recall, the Xtrakit Swift, Scimitar and Canberra were all done by Sword.
Sword did not pursue issues of any of those kits in their own boxing whereas MPM reissued several of the kits they did for the Xtrakit line under their Special Hobby banner.
Without Sword making their own editions of the kits and marketing them in the fashion that MPM would, perhaps the lack of market exposure undermined the kit.