We, www.colourprofiles.com , developed a 1005 patch target that seems to achieve better grey balance than the default GMB chart, it also helps using a DTP70 here too. It all fits on a single page as well.
If that's the goal, the 2500 patch
post optimization process available using i1Profiler can aid some output devices quite well. But it's a secondary process that requires more pages to print then send in but I've seen quite noticeable visual improvements to many of the ink jet printers I've profiled.
MT's profile generation is good, i1P's a bit better, one of the actual improvements over the older software (so kudo's to X-rite just in case some think I'm too hard on them).
Next week I hope to test custom target generation from the new version of ColorAnt vs. i1P using the same number of patches.