Basically to cut a long story short, those bikes are cheap shit. Are you actually doing any mountain biking, or you just want a bike? In any case, for that little money you're not going to get anything great, but you will get a much better bike if you get one with no suspension at all, and V-brakes rather than discs. Manufacturers stick both on to make a bike seem more appealing, but they work terribly and increase the cost of the bike so they further skimp on the other parts.
If you can stretch to 180, this would be a much better buy. This is 185, it comes with suspension but it would be an ok bike. You also might like the look of it more. Giant are such a huge company that they can afford to get their bikes down a bit cheaper, so it'd be much better than say an Apollo for the same money. When you spend a bit more money, Apollo can make some ok bikes, but I'd always recommend going for an established brand over them.
If you can stretch to 180, this would be a much better buy. This is 185, it comes with suspension but it would be an ok bike. You also might like the look of it more. Giant are such a huge company that they can afford to get their bikes down a bit cheaper, so it'd be much better than say an Apollo for the same money. When you spend a bit more money, Apollo can make some ok bikes, but I'd always recommend going for an established brand over them.