I'm a fan of lock-backs. I would much rather tackle clamshells (and do) with a small locking folder like my Old Timer 5OT.
I helped my bro-in-law secure his sail boat for a storm last fall and needed to cut some old hosing to make rope shrouds/protectors. The 5OT handled both the cutting tasks (including splitting the old housing lengthwise) but also handled the task of punching some holes through the side of the housing. I wouldn't have wanted to have attempted that with any slip joint that I own.
As an added bonus, I find the thin profile of a "gentleman's" size locker to be easier to carry in my pocket than any multi-blade slippie that I own. Taking nothing away from the peanuts and small slippies, the small lock backs are, for me, the epitome of the little knife that punches way above its weight class. But... at the end of the day, people should carry what makes them happiest.

schrade-5ot by Pinnah, on Flickr
I helped my bro-in-law secure his sail boat for a storm last fall and needed to cut some old hosing to make rope shrouds/protectors. The 5OT handled both the cutting tasks (including splitting the old housing lengthwise) but also handled the task of punching some holes through the side of the housing. I wouldn't have wanted to have attempted that with any slip joint that I own.
As an added bonus, I find the thin profile of a "gentleman's" size locker to be easier to carry in my pocket than any multi-blade slippie that I own. Taking nothing away from the peanuts and small slippies, the small lock backs are, for me, the epitome of the little knife that punches way above its weight class. But... at the end of the day, people should carry what makes them happiest.

schrade-5ot by Pinnah, on Flickr