Often remastered CDs don't sound that much different -- after all, they aren't remixed. The goal is usually to obtain the highest quality master tapes possible and use current digital techniques to clean it up without changing the sound.

By contrast remixed releases such as multichannel DTS, DVD-A, and SACD can sound significantly different. I've read that Rush - 2112 is planned for multichannel remix, but I don't think it's yet available. If you have surround speakers, get a couple of DVD-A albums and try those. They will play on most DVD players. Here's two sources: http://www.dtsentertainment.com/, http://buydvdnow.com/Merchant2/merchant.mv?Screen=CTGY&Category_Code=D