I recently purchased the 100 spindle of Princo Silver/Blue CDR from DisksDirect.com for $29 plus shipping and handling. It came out to around $36, so the Amazon price isn't really a deal other than the free shipping. I have burned these discs at 6x without any problems, but due to the limitations of my burner, I cannot confirm any higher speeds.
While I know there may be better and cheaper discs out there, one of the reasons that I purchased these discs is because Princo discs are the only one that plays in my Toshiba standalone DVD players (i.e. SD3109 and SD2200). So it's really nice to be able to play music that I've made backups of or play family VideoCDs that I've burned. Other than that, I have to admit that the discs are cheap. They do not come with any protective surface. They have a silver, unbranded top and a blue bottom.