As of the newer (not most-current) revisions, I never experienced stutters in FMV in any game. Maybe I try Final Fantasy XII (12) again, but I'm not sure where my disc is.
1. Make sure your NAS/PC is serving the data-stream fast enough.
2. Make sure your router isn't blocking anything or slowing it down.
PS2 V7/DMS3 V2 (FW:2.4b7); Seagate Baracuda 200GB
PS2 V7/CC1.0 (FW:34 hacked v2 BM:2.1.6); Maxtor DiamondMAX9 PLUS 160GB
PS2 SCPH-30004R; NoMod+NoLaser
3xSony MC 8MB
MAX/Datel 16MB with Boot-CD
Custom FMCB 1.8b+ Beta-Build, my AIO 0.5, Sony&xRhino-Linux