I use one for work all the time. Infact were on out 3rd one. I think there great, 174bhp standard form do around 30mpg and tax is under £100 a year! We do allot of towing with ours and it's ideal.
The only thing I would say is make sure you get one that’s in warranty as we've had some big problems, like the rear wheels not driving on the 4x4, and the first one we had was an auto and that just decided to die and not go into gear.
Anyway we test drove loads of double cabs. And out of the lot I would have a Navara (new shape) or the new Hilux with the 3.0 Land Cruiser engine.