I've been to both Harlan (several times, a lot actually) and Windrock (twice).
First time at Harlan and Windrock I took my Tacoma (2010 with some lift, factory locker, 33's and some skids and sliders). Had a blast with it. I didn't do anything super hard but I still had fun.
With Harlan compared to how it was then, ~2012, it may be a trick getting up from Putney at the switch back / rock ledge place with no locker. It's sharp and the use and elements had made it a touch sharper and the rock more pronounced.
Campgrounds I would compare them the same. Both have nice facilities and neither I nor the groups I have been with have ever had anything messed with or stolen, and that's tent camping with tow rigs, trailers, and a atv for trail scouting. Windrock does have a key code door thing to get to the shower houses but I've never known any random people to show up in the ones at Harlan.
Windrock seems to have more gravely-ish roads and easy stuff but it's an all around bigger place.
Both are about the same distance from me, ~2/3 hrs, but I like Harlan more for some reason, even with my current rig. Maybe it's because I can navigate it without a map idk, but Harlan is my personal favorite.
Go to both in time and see what you think. You can ride easy stuff, scrape a rock/tree, or roll over either place.