The only one that I have used is the Ritek R03 that you get in the office depot branded DVD+R 8x and the (MIT) Maxell's DVD+R 8x. They have been very good to me with no coasters.
I know what will be said about the others, but have no first hand experience with them so I will reserve my thoughts.
i've used all of 50 Ritek G05's and every single one burnt fine, playback fine.
as to Datawrite they use varying quality in disc manufacturers so you gotta be careful which ones you get. see this link from my sig, or one of the links within the link.. http://forums.afterdawn.com/thread_view.cfm/232406
Have used several hundred Ritek G-04 and G-05, I am very happy with them. and 05's in the past few years which I have purchased from Office Depot or Shop4tech, never had a problem with them but have since changed over to Fuji MIJ's (Taiyo Yuden disks) which seem to be better quality and a little easier to find right now. Have not been happy with Office Depot since the new 16X media has coded out to RICOHJPN disks.