said by Teasip:do you find similar service stability and speeds
Yes
VZ would slightly over provision the line speed. FT would slightly under provision the line speed.
Issues comes with calling support / billings. Support number is mainly for DSL issues. they will punty you over to another dept or ask you to call a different number for Fios.
Billing will be find or it was for me. Until you change plans. Then it can be a real PITA esp if you are grandfathered into a plan with add on's. When I ordered FT Fios TV it took the person over 60 minutes for them to process my order while I was on the phone.

I'm at month 4 with billing issues as a result of changing from a grandfathered VZ plan that was over 5 year old and moving to a new FT plan.
Over all they are as good as VZ.