backups and restores: -Fc vs. -Ft

All this talk lately about problems using -Ft when restoring backups...I've always used -Fc. What other advantages/disadvantages are there to using the custom format as opposed to the tar format, besides the fact that tar has never reliably worked for me? Why are all you other admins (seemingly) dependent on having tar working, besides that it's really really cool when everything works as expected?

Thanks in advance for the enlightenment :-)

p.s. - fyi, here's my backup/restore method (I don't use the contrib lo, I just use the regular built-in stuff.):
pg_dump -Fc -obf dumpfile -U mysuer mydatabase
pg_restore -Fc -s -U myuser -d mydatabase dumpfile
pg_restore -Fc -ao -U myuser -d mydatabase dumpfile