As much as I like pickup trucks, I've never quit understood why anyone would buy one as their primary vehicle -- especially someone with a family. I had an absolute blast piloting these gargantuan vehicles around Southern California while researching the Heavy-Duty Pickup Truck Comparison. But to actually use one purely as personal transportation? That's like buying a four-bedroom house, then boarding up two of the bedrooms.

Well, friends and neighbors, I've had a change of heart, thanks entirely to GMC's new 1999 Sierra extended-cab pickup. I can tell you -- with a perfectly straight face -- that this is the first full-size pickup that doubles as a family car with no compromises. Well, OK, it makes one compromise, and I'll get to that in a bit. But just as importantly, the all-new Sierra once again raises the bar for utility and modern design in a pickup truck.

For years, GMC has been selling clones of Chevrolet's pickups. GMC wanted to differentiate themselves and move upmarket -- probably a good idea, since parent General Motors has way too many divisions, and now is not a good time to be seen as redundant. So when the pickups were redesigned for 1999, GMC's version got unique sheetmetal with a hood that arches above the raised headlights, and a prominent ruby-red GMC logo on the grille.

But the real news isn't outside -- it is inside, starting with the extended cab Sierra's back seats. Other pickups get rear seats that are temporary perches at best, better suited to small children, pets, and groceries. Not so the Sierra -- real-live six-foot adults can fit comfortably, with as much thigh support and legroom as they'd find in a mid-size sedan. They even get their own cupholders.

Alas, there's one glaring problem -- the Sierra's extended cab is only available with three doors, while the competition offers four. The Sierra's back door is on the right side, where it is best suited to loading folks from curbside. Ironically, I missed the left-rear door most when I had something inanimate to haul; it's nice to be able to pop open the door and toss my groceries or my laptop computer bag into the back. Walking around to the right side or hauling that stuff while climbing into the cab gets real old, real fast. GMC won't comment on whether or not a four-door will be made available, but I'm sure they'll offer one soon -- consumers seem to demand it.

It's not just the back seat that makes the Sierra such a great truck to live with. Front seats are roomy and comfortable -- though short drivers may find them to be mounted a bit low -- and oddments space abounds, including a large bin between the bucket seats. There's a covered compartment that holds three CDs, but the door swings upwards, making it impossible to see what's inside. The flip-up door covering the power outlets (three of them) has the same problem. These doors should be hinged at the bottom so one can easily see what is behind them.