Awesome! I've had this product for about a year and it has held up and is great. Haven't lost a chain yet, perfect with my XT 1x setup. Don't really notice any difference with the oval tho, but it can't hurt. Glad I didn't spend way more when this works just fine. And yes the instructions are ridiculous like other reviews mention.

40 teeth are better than 36!
The extra four teeth make the difference between grinding out a climb and getting off the bike to hike.
Hind sight, I may have even been better off with the 42 tooth version, but I wanted to test this out first. I love it!
Double check as to whether you'll need the Wolf Tooth Components Lindarates Goatlink to extend you derailleur for the big gear.
I have Shimano and I did need it.

Replaced my 11-32 Shimano cassette with one of these. I had to get a bigger chain, but after adjusting the B-screw everything is working great, install was easy, adjustment was simple and now with 5 rides on the new setup I can say it all works really well. I like the increased range from the 42 tooth granny. if you have a 2x10 Mountain bike you might consider one of these for a little added range without spending a bunch of money.

This cassette was easy to install once I understood how to use a chain whip. Man, did I feel dumb once I figured it out...shouldn't have been so hard. However...once I was able to get the old cassette off, this went on with ease and looks really cool. The red aluminum that gleams through is killer. I installed this on my 2014 GT Zaskar. Has two chain rings in front and 10 in the back. This new cassette has bigger rings in the back and it made getting the chain just right a bit of a challenge. With my inexperience installing cassettes, it was 2 chains later I got it working OK. Not great...but OK. I blame my lack of bike cassette installations. So, on my front 24 tooth small chain ring...all is great, up and down the cassette perfectly. On the bigger 38 tooth chain ring, I cannot get the chain to go all the way to the biggest cog on the cassette without a grinding, "Oh Crap!" inducing mess unless there's so much slack in the chain, that it flops around like a wizard's sleeve. So, I opted to keep it tight. And really, when would I use big front and big back cogs? If I consider myself a good mountain biker, then the answer is, never.

works great & great price, I have them on both of my bikes and on my second one on my nomad.