@grievoustim will know more than me, but in general all the big manufacters mtb offerings around that level are pretty much the same quality, all the same parts on similar frames. So you can pretty safely just pick a budget, pick one you like the look of and go for it.
(one thing to look out for would be type of brake, they’re all disc brakes now on mountain bikes but some will be mechanical (with a cable that pull the brake, like the old days).
Higher spec bikes will be hydraulic (a sealed system like you get on a car), these are generally the best but a hell of a faff when they go wrong.