Definitely YMMV territory.
I like the idea of fixed blades. I like using them. I never ever carry one. But then, I hate anything of any kind on my belt.
Around town, a fixed blade just offers no value to me.
Way, way, way too much social friction. And I'm not going to even think of carrying a fixed blade with a blade longer than 4" around town and in that size range, just much easier for me to carry a large folder in my back pocket. Way, way, way less social friction. Way, way, way more comfortable. Just a win on every count.
In the woods, I only carry a 4"-5" fixed blade on the rare trip that I'm going to be making fires regularly and that is rare. More often than not, I just carry an EDC type folder and that's more than enough for everything I do.
As far as locking vs slip joint... I don't much matter to me. I carry traditionals *almost* exclusively. I pick knives based on other factors than locks.
This thread needs some pictures. Slip joint goodness in the rear pocket.
Case Large Sodbuster and Micra by
Pinnah, on Flickr