I run an Axial 32 in a Sav 4.6SS with ext and lowered tvps. I wanted something better than the stock 4.6, and boy is it ever!!
Sorry, can't directly help with experience on the 28, but the 32 has been sweet and reliable, easy to start and has held a tune. If that carries over to the 28, it'd be a good choice. Hopefully, you'll get someone who has one to reply.