I use Rhino ramps, no complaints. Quite convenient for oil changes, etc. There is a rubber boot that falls out quite easily. Do not lose, as that is what keeps them from sliding.
I am lowered on VWR springs. To get them up to the tire I need to give them a swift kick to wedge them between floor and bumper.
I've had my Rhino Ramps so long (at least 14 years) I don't remember where I got them (most likely Wal-Mart) or what I paid for them. But they have been well worth it. I just looked at mine and they are Made in USA; not sure if new ones are. They have lots of internal ribs for good structural rigidity. Biggest vehicle I've had was my '02 Mazda Tribute (sister of Ford Escape) with V6 and AWD.
Only issue is they are a bit bulky for storage and don't nest as metal ones do, but you can place them head-to-toe when putting them away. (I stand corrected, apparently they do kinda "nest".)
Also mine have the rubber pads but they still tend to slide. This hasn't really been an issue except when I used them for my RWD Miata. As the rear wheels keep driving forward, there is just a bit too much momentum for them to stay put. I haven't fallen off, thankfully, but it makes planning the workspace around the car (yes even a tiny convertible) a bit harder. I used stacks of bricks to try to limit the sliding.
I just used them last night for doing the first oil change on my Golf - no issues. It's been about 8k since I bought the car in July. It was a nice day and I didn't want to wait on getting an oil extractor. With a stock TSi suspension, I had just enough access underneath (though more would have been nice).
Also be sure to use wheel chocks. (And don't forget to take them out when driving off the ramps, as I often do.)
EDIT: I just looked at the listing on Amazon; these look different from mine. Mine are more "contiguous" where the new ones appear to be like connected blocks. Not sure if it is this design which is leading to complaints.