Pros
(+) Positive working environment: awesome co-workers, experienced and friendly people; understanding team-leads and managers who would reward any work you did above-and-beyond; helpful support staff regarding insurance, deposits and payments, and day-to-day operations. (+) Unique work: Experis prepared and delivered me to a large client with professionally high standards; formal introductions were made between client leads and our teams; training was paid for and covered by Experis before integration into the client's systems and operations.
Cons
(-) Sub-optimal pay: mid-level (experienced and professional) technicians could be getting paid as and found at entry-level positions; you'll tediously work your way up the ladder through very competitive projects, don't expect any bonuses; bigger clients and projects do not always mean a higher pay rate. (-) Working along the market's demand - you're being placed somewhere Experis can find, if your region has cut demand then you'll find a cut in your available projects. You may be crossing your fingers towards the end of a project because you don't know if there will be another project after or if you'll be one of the ones to get placed. You won't get "fired", there will simply be "no projects for you to work and clock in time" on.