sys-fs/{exfat-utils,fuse-exfat}-1.2.7 have been in tree since ages and I use them on amd64/ppc/ppc64 without problems for a long time.
I would rather jump to 1.2.8 since it was a very minor update. Have you encountered any issues with that version?
1.2.8 runs equally well on my boxes (I use it for data exchance regularly). I simply thought it to be too new for stabilization.
x86 stable
amd64 stable, closing