I have a customer in the High End Consumer Packaging Business. They send high-res graphics files around alot... for 12 pack beverage containers and PS3 game cases and the like. We did some testing for them and it was pretty decent optimization.
Un-Optimized
File Ver. MB Start Finish ET
Original 147 10:21:36 10:44:12 0:22:36
Changed 208 10:44:58 11:05:24 0:20:26
Optimized - COLD
File Ver. MB Start Finish ET
Original 147 11:27:51 11:40:15 0:12:24
Changed 208 11:41:24 11:50:53 0:09:29
Optimized - WARM
File Ver. MB Start Finish ET
Original 147 11:54:37 11:57:35 0:02:58
Changed 208 11:58:21 12:02:43 0:04:22
As long as your data is not already compressed or encrypted I would think it would be ok. Always test though.