Neither system is designed for factory production use, but both do a really nice job. Both were designed in the USA and are precision manufactured in the USA by INCRA (the I-BOX is based on my original licensed design). The differences are:
The I-BOX is a dedicated box joint jig that can only be used to make box joints on a table saw (with dado blades) or a router table. It also allows you to make specialty box joints that are very hard or impossible to make with other jigs and methods. I think I can safely say, that it is the best box joint jig on the market and exceeds the capabilities of all DIY box joint jigs, including Lynn's and Mathias Wandel's leadscrew-based jigs.
The LS is a precision, indexing fence system that can be used as router table fence or tablesaw rip fence. It can also be used to make box joints on both, and dovetails on a router table using a right angle fixture that rides along the fence. The board width capacity of the LS is limited while the capacity of the I-BOX is essentially unlimited.
The I-BOX is easier to set and use to make box joints, however. You stack the dado and quickly set the jig. It doesn't matter if the dado is not a precise fractional width- many dado blades aren't- since you set the I-BOX to actual kerf made by the dado. With the LS, you select the size joint you want then carefully shim the dado until it makes a kerf that is precisely a multiple of 1/32".
I have both, but due to ease and speed of setup and operation, I only use the I-BOX to make box joints.
If you plan to make a lot of small decorative boxes, vary the finger size, and might want to use some unique looking box joints- get an I-BOX. On the other hand if you will only make a few boxes a year- get an I-BOX.
