I have and use my poor man's strop from Whipped Dog. I'm considering a Hart Razor eventually and I was wondering if my existing strop would suffice. Do I need to upgrade that too?
It will work fine. Want vs. Need. You don't need another one but some of the fancier ones are very cool to use and probably just a tad easier to use but the poor man's strop is good and will keep your Hart sharp.
As was mentioned there is no need for a new one, although a more "luxurious" strop does add considerably to the "experience". Kind of like how a nicer smelling soap and nicer brush might make the shave more enjoyable, where a puck of VDH and a Tweezerman is more than enough.