Which appeals to you most?
Both have a great steel and are tough ti frame locks.
Don't worry about the Ti wearing against the steel.
It's a classic lock design and works well.
As for the steel insert, people feel it adds extra strength.
The Southard is a little smaller and thinner.
There have been a few issues with fit and finish on the Lionspy's however these have been far and few between so I wouldn't worry about it.
The Lionspy is extremely beefy and a little heavy in the pocket.
In my opinion, I like the look of the both knives. I love the way the Lionspy feels in hand and I do like beefy knives(I prefer them a bit smaller though). For an all around knife that could handle anything and take a beating, get the Lionspy. For a more regular EDC type knife, get the Southard.
But say if your job consists of harder use where a beefy knife is best and looking more "friendly" doesn't matter, get the big beast lol. If weight isn't a concern while carrying either at work or home the Lionspy is a good option for that.
However, if you want just an all around EDC knife that can handle your daily tasks, is lighter, good steel, and overall a little more pocketable and more EDC friendly, then get the Southard.
It really depends on what you prefer.