I have a Gamecube with Icecubed case and Viper GC Extreme.
I must say its probally the best modchip for the GC, extremly great. Newest bios have support for special drivers for each dvddrive for the GC, which greatly improves readability. My GC would never read my Verbatim DVD-R, but with the patched bios for my dvddrive it read it instantly without a single DRE. Sure you might have to adjust your pot, but its very easy. If you dont want to, just try various media until you find some that work.
Also Viper GC Extreme can store .dol files on the flashmemory on the chip. So you can have your emulators on there and only games on the dvds.