Hey glen3-88,
I think your comment of "why wouldn't the Coiltek be AS GOOD NOT BETTER" sums it up pretty well.
In talking to, and reading, users comparisons, there seems to be no definitive advantage, nor disadvantage. It simply comes down to personal choice.
We have to keep in mind, opinions are just that, opinions. They are not scientific facts, mostly based on personal, subjective, reasoning based on the individual conditions of the person rendering that opinion! They tend to be scattered all over the map for that reason.
That is why the BEST thing anybody can do when choosing equipment, is use THEIR OWN conditions as the basis for their choice! Their own personal preferences, detecting conditions, locations in which THEY will be using the equipment.
You mentioned a 7" coil, there are none available in that size. The current sizes availabel are 11" round (comes with the CTX), 6" round, and the 17" , plus the new 5x10" offering from Coiltek. All are DD configurations.
Best of luck in making your choice. Make it based on YOUR conditions, and it WILL be the right one!