Computer bags are like family: We trust them with our deepest secrets.

Brenthaven (www.brenthaven.com) is acutely aware of the relationship. Its entire computer line carries, for example, a lifetime warranty against structural flaws. The company says that fewer than 1 percent of customers who buy its shoulder bags, wheeled cases and backpacks return them for fixing.

“We have people who have had our cases for 15 or 20 years,” says Tana Gudbranson, Brenthaven’s vice president of marketing.

And I’m one of them.

I purchased my first Brenthaven wilderness pack more than 20 years ago. It withstood hail-pounded mountain treks, white water canoe mishaps and outdoor rock concerts better than most of my friends (and certainly both my brothers).

The zippers and snaps never wavered or failed, even when hastily overloaded. Seams never frayed. And its lightweight fabric never faded or stretched out of form.

That said, most of the design of Brenthaven’s new Messenger Bag did not disappoint. Available in red, blue and celery, the colored versions ($84) are expertly crafted of double-woven Cordura.

A black model ($89) features “ballistic,” a military-grade nylon that “self-heals” from pen jabs and pokes.

The lightweight form is rich in function. You’ll find the two elastic-cinched exterior side pouches, for example, perfect for easy access to cellphone and PDA while on the move. Two zippered front pockets – one shallow, one deep – make quickly grabbing writing materials, business and ID cards almost fumble-free.

Inside the top-loading cargo space, there’s a slot for a computer with a Velcro strap to hold it firm.

And that brings me to the carrying strap – the only disappointing feature of this model. It is adequately adjustable to the tallest and shortest of road warriors, but the shoulder pad is not rubberized or slip-resistant.

As a result, when carrying heavy loads, the strap tends to slip down the shoulder. Constant tugging is needed to keep it riding high.

and often I find myself carrying it, briefcase-style, by the handle.

Computer bags have come a long way from the days when they all seemed crafted from half a cow of heavy, inflexible leather. Today, manufacturers such as Targus and Case Logic are all producing well-made products similar to this one.

But given my history with this company, make mine a Brenthaven.