weight-plates-steering--537.jpg
Something like this, Tom. The rubber is harder than that on a typical bumper plate. It costs half of what a bumper-plate costs per kilo. Hence the attraction.
They are not a substitute for bumper plates and cannot be dropped. If I were buying plates, I would not choose them. However, if they make you happy, then go for them.
If I needed to buy plates, I would get nice ones. Lots of people like to say, "Plates don't matter. Weight is weight." I don't agree. Having plates that weigh within a fairly tight percentage of the marked value is nice. Good plates are also the correct diameter for spacing off the floor, or at least close to it. Good plates also are machined so that they fit snugly on the sleeve. I have never regretted buying the best quality I can afford.
If I had to buy iron kilo plates, I would get one of Rogue's calibrated sets. If I wanted bumpers, I would probably get Rogue's HG series. If pounds are an option, it looks like Rogue is subbing to Ivanko for their iron hammertone series. Those are nice plates, too, and cost less than the calibrated versions. York also makes good iron. You can buy them from Rogue, but you can probably get a better deal by getting in touch with someone from York directly.
I recently found Troy ho plates (lbs) and they are awesome. They're machined iron calibrated plates, so they're within 2% of the stated weight like the hammertones, but much cheaper. You can get them grey or black. Here's a place that sells them for a decent price - Troy HO Steel Weight Plates | Hammerhead Strength Equipment.
To echo Tom: cast iron is cheaper still, but cast plates are not built to tight tolerances and can weigh anything, so it can be harder to train with them. The Troys aren't pin-point accurate like the calibrated plates, but 2% is pretty tight (less than a pound for the 45's). It can also be annoying if you get cheap plates that don't fit great on the bar and they slop all over the place on pulls. That can put the bar lower on your shins. Call me spoiled, but I like using plates that put the bar at the correct height on the floor, fit on the bar and weigh what they're supposed to. Plus, iron plates are cool lol.
York makes machined calibrated iron plates with their "legacy" line, but the damn things are like a good half inch shorter than the standard olympic height of 450mm.
John Janacek had an awful experience with Troy. Based on his story, I cannot recommend them to anyone.
Just my 2 cents: I train with those rubber coated plates, and I can't endorse them, unless they are WAY cheaper than anything else. They cannot be dropped on the floor like a bumper, and are way thicker than regular iron, so worst of both worlds, really.
I am not denying Janacek's experience with the Troy bumper plates (I've actually never seen a Troy bumper plate in person), I just want to add my recent experience with Troy plates as I just built out a home gym a few months back. I purchased the Troy Premium (deep dish) cast iron plates, within 2% accuracy. The price was decent, and so far I am very happy with them. With that said, I have zero history with Troy customer service (hopefully never need to). These were the best price I could find on new plates online.