It's hard to offer advice without more details. Your status suggests 100+ nights and an ambassador, but what do you want from a frequent sleeper program?

Note that HH gives Gold to AmEx Platinum charge card holders and probably others, so you probably needn't start from scratch if you decide to go that route.

Could the Hyatt program work for you in terms of its footprint?

I would avoid making immediate rash decisions, but if you've already requalified for PPwithAmb for next year, you could use your remaining stays this year to explore alternatives or even do a challenge (that covers all of 2019), but remember than status matches/challenges are in principle supposed to be once in a lifetime, so the opportunity shouldn't be wasted.