Regarding plate carriers, I've got a Ferro FCPC. The shoulder buckle is a nice feature for quick egress, and is why I chose it. I only use for occasional LARP purposes though. Seems pretty durable
I have a Slickster, it is my lowprofile rig, and it is slick right now so I'm entirely unprepared to write up a review on it. I will say I'm not a fan of the elastic cumberbunds on account if when running they slap my back a bit. When under a shirt or loaded up less of an issue. I'm a skinny (Boney even) guy so maybe its a me problem.
Generally there are 3 plate carrier set ups to plan around. I'm using these terms a bit willynilly because this is off the cuff stuff.
1. Tactical: Plate carrier to protect you and carry some spare mags. Small first aid kit and TQs are welcome but if we have an admin pouch it is small and essentials focused, just enough to fit a resees fastbreak, spare batteries, Leatherman, and your nightvision kit in. Its light on sustainment and is probably used in conjunction with a battlebelt or warbelt. This is your kit for rapid deployment and skirmish. Most people can stop here.
2. Assualter: Sustainment heavy, plenty of ammo at the ready with a heavy focus on direct action. Direct action ironically often means hours of shooting at people who you can't see and are too far away to lay effective lethal fires on. It has an admin pouch with anything ranging from NVG kit, to maps, to communication gear, maybe an optic magnifier or binoculars, even snacks. It goes without saying divy this stuff up among friends and in your pack, these are examples. A dump pouch I personally see as essential but they are somehow less popular these days. You certainly have an IFAK either on your belt or on your carrier. This is the kit for looking for a fight or holding a position. Some side soft armor to protect from frag completes this rig for its mission set.
3. Low profile: You wear it under your shirt. Its not a load bearing, it maybe has a mag or two carefully placed for accessibility if the weather appropriate clothing permits. This is nice for not getting shwacked. A little drawstring backpack with essentials (like snacks!) and an IFAK is all you get for sustainment.