The LBS and the pedal manufacturers share in the "learning curve" issues of clipless pedals for commuters. Ive bought two pedal sets through two different LBS and either the manufacturer or LBS had both of them set up for road race level tensions. Nearly immediately reducing the tension (reducing the difficulty of removing the shoe from the pedal) turn insecurity and fear into revelation and success for commuting. (I have spd's)

That plus you always buy a mtb style shoe so you dont rip up the hardwood floor (or worse, get blamed but not be responsible)

Other notes -- its also a matter of the commute length -- at 5 miles or less, whats the point of spending the xtra money for the pedals and the shoes.

Locking your feet in one place will affect any knee issues so be willing to adjust your cleat angles.