Pros
Various recruiter types are pretty good about keeping in touch. You're not completely invisible like with other contracting companies. Quick response from the payroll department for anything timesheet-related. They have summer and Christmas parties. Account people will come around and hand out swag or Starbucks etc gift cards. They will occasionally take you out to lunch - nice, but realistically it's mostly to kiss up to the client. Overall they're above average as far as contracting/recruiting companies when it comes to contact.
Cons
Their negotiating tactics are pathetic. Don't believe anything said on the phone - get it in writing. The account managers are well-trained to sound sincere when they ask "Is there anything you need?", but if you ask for something specific there is never any followup. They are excellent at glad-handing and pretending to care. Frankly, it gets to the point where one prefers a company that clearly doesn't care over one that constantly pretends to. Biggest beef - there was a large layoff; employees who had vacation benefits were told they had to use vacation prior to layoff date, which was a violation of state labor law (acrued vacation = wages already earned). Some employees who didn't know any better fell for it. Tek got paid regular hours by the client and then didn't have to pay out the vacation separately. This hurt many employees financially on top of being laid off, and was probably the sleaziest move I've ever seen from a contracting company. This kind of tactic deserved a poor rating.