I have a varavon s slider, along with the electric motor for powered slider moves. Can't speak highly enough of the build quality and PV have deals with them.

I like this. iFootage Shark Slider S1

Am thinking now about the Konova K2 120cm? Looks like good value.

I had that Konova and returned it. Little to wobbly, even with a payload in it's range. I actually have the Varavon S900 which is solid but I've already outgrown it's payload capacity so I'm selling it.

I'm looking at the iFootage slider as well, apart from the flywheel I also like it's expandable length, but I'd like a motorised option.

Edit: Just read on that red link that there will be an upcoming motor, unless they mean the Emotimo, interesting either way :)

For DSLR use, just try to get a beefed up version of Varavon (or the light ones if you need something super portable)), any of those will be adequate. You will have to be careful with the rails, they can get dinged pretty easily, and rust, so try to keep it clean, oiled, etc.

There is a reason for the higher priced ones, some of them have better motion, better design, others last longer, others are longer and take bigger payloads, etc. The iFootage is mentioned because it offers a lot at that price point and is, practically speaking, a better deal compared to the lower budget ones.