If you've booked through a third party or travel agent then it's a lot more complicated if you want to cancel and you're going to have to read the small print. Have you booked with the hotel direct? If so and you're not happy then you can cancel without losing anything (providing you give the required notice - usually 72 hours) and book elsewhere. Its biggest drawback is its poor location - way north of the main action on the Strip and the amount of time and money you'll spend on cabs or monorail rides getting there. I havn't stayed at Sahara for some years but basically, you get what you pay for - perfectly adequate, clean accommodation that, compared to more expensive Vegas hotels is pretty basic. A lot of people write bad reviews just because they get sensitive about one small incident during their stay or because they just like to be awkward.

I could give a lecture here about doing your research before booking but I guess that won't be of much comfort to you right now! First of all take all reviews that you read with a pinch of salt.