I have both the datacolor and the Munki. I bought the datacolor first, and while I got decent profiles from it I almost always had to tweak things, as profiles were indeed on the warm side to start with. In addition, measuring each patch by hand was taking quite a while, and often resulted in some re-measuring due to errors.
Since I got the Munki, I am happy with the results, I waste little of my time on profiling and get to enjoy my printer by creating what to me are lovely images.
Profile 'tweaking' (optimization in munki terms) is still possible, just more automated (which has the side effect of being faster). I have evaluated prints side by side from the same printer (epson 4900) on the same paper profiled with both the munki and the datacolor. In the end, after tweaking, editing, optimizing etc I was able to produce pleasing and accurate images. Going forward, I plan to rely mostly, if not exclusively, on my munki as it gets me there in less time and with less feet of paper used to create profiles and test images.
Of course, my experience does not have to match any other and my goals in profiling my printer might be different from yours.