Center is fine, but up front and real close (lower seating area) for any Cirque show, La Nouba included, is not necessarily the preferred seating section. If you are wanting to see facial expressions, muscles, maybe a few (maybe a lot) beads of sweat, up front is the place. However, in all Cirque shows (I have seen 5 different Cirque shows, some multiple times....they are great), there is a LOT of action high up, as well as some action that takes place on the walkway between the levels. If 'up front', you will need to be looking up, as opposed to more or less straight out, for the high up action, and will need to turn around, rather than just looking, for the action on the walkway.
http://www.cirquedusoleil.com/CirqueDuSoleil/en/showstickets/lanouba/TicketsGeneral/seatingplan.htm
The very best seats, IMO, for the money, are Sections 203, 204, 205 rows EE.
http://www.floridaorlandotickets.net/cirque_seat_chart.htm (older seating chart, does not show the new 'up front and center', only difference is section 103)
In any case, the show is fabulous, enjoy.