I have a DC 14 (yellow). I like it. It doesn't have as strong of suction as I thought it would (the floor part, not the hose part) but it is sufficient. I've had mine for 2.75 years and there is something making noise in the motor, which I will probably have my dh look at, but in the meantime it's not affecting it's performance.
I have a Consumer Reports magazine from a few years ago that has reviews for vacuum cleaners in it. Their highest rated was Kenmore (sears) progressive with direct drive. Other good ones were Eureka Boss Smart Vac Ultra, Electrolux Oxygen^3, Hoover Windtunnel Bagless. The DC15 was rated #6, the DC7 was rated #13, and DC14 was rated #14.
If I had to do it over again, I would have looked into the cheaper vacuums, but the Dyson does work really well for jobs I need it for (cleaning guinea pig cages).