There is a frustrating side to these discussions that seem to come up
every few months.

The schweizer hook works well enough to justify not removing a
serviceable one.
Tost has not applied for STC's in the US that would allow trouble free
approval.
I have heard that it is tough to get a Tost hook approved with a 337.

The above reasons have prevented a flood of Tost installations. It is
hard to spend $2,000 on a hook that may take a year to get approved if
your FSDO will even approve it at all. It really isn't just a matter
of negligence when someone continues using a schweizer hook but rather
the proverbial "between a rock and a hard place". Maybe Tost will
step up one day and apply for an STC. I hear that a new and improved
schweizer hook may be on the horizon.

XF