Diamondback mountain bikes have been mediocre until about 6 years ago until made a commitment to produce a higher end mountain bike.
Take the Sortie 1, which is listing for $2400 but you can get for $1700.
versus the Recoil Pro, $1200.
You can compare part specs and it is pretty easy to see the high end Fox suspension and better shifters, etc, on the Sortie. But the most important thing is the frame design.
The Sortie has a more complicated linkage design, which means higher quality machining and forging. The Recoil has the simplest design, called a single-pivot.
Now we can have a long discussion about suspension designs, but when a company puts more money into their frames, it indicates a jump in quality.
I'm a bike snob so I want a high quality bike.