What are the key components to compare and contrast when deciding between hardtail mountain bikes?
Before outnumbering some key points I usually look when I want to buy a bike, I will tell you this: Ride them both. Form an opinion for each one and buy the one you think that comes better to you.


Compare their peripherials (suspension, drivetrain, brakes etc). Check what their manufacturer made them for and the warranty provided. If you have two bikes having drivetrain from the same manufacturer, it is wise you choose the one that might have a better series on (why get sram x9 if you can have xx for example).
What is the frame warranty from the manufacturer?
Make sure you know what are you spending your money to. Both bikes you are looking at are expensive xc bikes with some top peripherials. What discipline do you really want to ride? Do you need something that expensive? Are you a competitor, or just a fan of mtb?
What is your experience level? Beginner or pro? Spending a huge amount of money on a bike as a beginner is wrong. Learning and evolving on a reliable, yet not top of the class bike, will make you a better rider.


I suppose you are a beginner. If you are not oriented to racing xc, get a cheaper bike. Once you have learned technical stuff and have concluded to the ride discipline you prefer, get a serious bike.