Just spent a week riding with the ION's CS Freeride harness.
To be perfectly clear - I can only compare it to my previous harnesses:
-Vertex Select which was a bit of a wrong model for my needs and it was a size too large (I'm sort of between Medium and Large).
-Manera Exa which I really liked but I'm an idiot with principles and it had to be unloaded.
I haven't cared to even try the Ride Engine as I don't like to be running along with the herd and there weren't any other brands hard shell harnesses to try on locally.
Anyhow, overall - I was very happy with the CS (got the Medium for my 33 waist). I'ts not supper-stiff, but it's very firm, sits really nicely - almost locked-on - on my rather waist-less torso. Only pressure points that I've developed after a week of fairly agressive riding - came from the spreader bar working into the rib cage - which I still have to fiddle with and adjust the straps properly. I've also noticed that it doesn't want to slide around whenever riding toeside - I'd be looking into the WAVE model if I was into hardcore surfing. And it still creeps up along with jumps and tricks - perhaps a notch or two less than some other harnesses which I owned in the past. Hey, not everyone is born with Apollo's waist!
Speaking of the spreader bar, the one that comes with CS-harnesses seems more compact than these supplied with 2018 Vertex and Apex models.
And the new lever-lock system is fantastic! Really liked how it operates, though I've caught my-self heading out a couple of times with the lever being in "walking-around" mode. Had to develop a habit of fully-unclipping the whole thing when not riding.
If I had to rate it - I'd say that CS FR is tons better than the EXA - more comfortable to ride and more comfortable to clip in/out.
It wouldn't be fare to compare it to the Vertex - later being a model targeted towards surfing and which it does beautifully.
As I was suspecting - a hardshell harness is a royal PITA to pack for traveling as it can't be unfolded flat. At the end, mine - being a size medium - ended up in my carry-on backpack. Your millage could very depending on your harness size. And having been on a few trips with the EXA - it's so nice to come back to a spreader bar with no idiotic flaps and which doesn't take up too much space in the main luggage.
Handlepass leash is removable and there are D-rings on both sides for a safety leash.
Good stuff!
And my lower-back was a happy camper too.