I recently received the TF100 test kit and it's great, but I do have one thing I liked better about the K-2006 kit. The pH test in the K-2006 uses a larger comparator and had a scale of 7.0, 7.2, 7.4, 7.6, 7.8, 8.0 which I find easier than the TF100 smaller comparator that has a scale of 6.8, 7.2, 7.5, 7.8, 8.2. Though it's nice to have the extra range down to 6.8 (in case of doing the "lowering TA" procedure), I normally just want a more accurate pH reading in the normal range of 7.2 to 7.8. I also find it easier matching the colors in the larger comparator tube.
By the way, having the CYA test measure down to 20 ppm is great. I had separately bought the Taylor K-1720 a while ago just to get that capability.
Also, I noticed that my DPD powder in the TF100 was more granular and gray-purple colored than in the K-2006 which was a white powder. Is that normal? [EDIT] It seems to measure chlorine OK -- it just looks different. [END-EDIT]