We has two users with SVGA II more than a month with no issues...
If the view 5 agent worked fine to you, you should plan to migrate to vCenter 5 and Composer 2.7, so you can continue to use view agent 5 and composer.
The interoperabilty matrix shows vSphere 5 is compatible with View 4.6.
http://partnerweb.vmware.com/comp_guide2/sim/interop_matrix.php?