I don't think the SoD is tougher. Infi is VERY tough. The SoD may be better for you though for the following reasons:
It is plenty tough It is lighter and I'm sure your gear is already heavy It is an easier length for carry It is less expensive It is a better length for a generalist knife
Now if you can find a SFNO, especially the LE, I would pick that one over the SoD. <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />
Reconseed, what do you use for your small knife solution?