Hey Cliff. Generally the WTK are almost exact copies of the Dietz designs. There are some small differences. One is that the WTK fill caps are "fiddly" while the Dietz' seem to go right on. This is mentioned in one review online. Sooting is a function of time, adjustment and wick shape. Sooner or later they'll all soot up and will need cleaning. You're right that the globe on the smaller lanterns is easier to clean, especially if you have large hands. One problem is that most people light the lantern adjust the wick and then walk away. As the lantern heats up, what was once the proper adjustment no longer is, and so sooting starts. It's worse with the bigger, more powerful, lanterns because the difference between cold and hot is bigger. Lanterns of this type usually take about 5 minutes to warm up before the adjustment will be the one for the long run. You can either stand there for 5 minutes and fiddle or come back in 5-10 but by then they'll have started sooting.
Another issue is proper trimming of the wick. Perhaps because the burner is rounded, some people trim the wick to match it. But wicks burn best if they're trimmed straight across. Some find that rounding a very small (1/8") corner on them seems to work but that's not been my experience. Best to use a sharp pair of scissors so there aren't any loose threads left behind and so that the cut isn't ragged.
This stuff used to be common knowledge when these lamps were in common use but nowadays most people's experience comes from seeing them in movies and with a large segment of the population not bothering to RTFM (read the f'ing manual) some people have lots of problems with them. The WTK site is a wealth of information but you have to go looking for it.
I prefer to have all my lanterns of the same model so that I only have to stock one size of globe and one size of wick. If I have two sizes of lanterns, Murphy's law will see to it that if I need a wick, I'll be out of the size that I need.
I agree with you about using lamp oil and that kerosene works but is a little smelly. My nose is pretty sensitive but if I use kerosene outdoors it doesn't bother me much, but indoors I find it overpowering. The lamp oil is fine though. Never tried diesel fuel but if you use it I suggest that you change the wick before using lamp oil again, it will probably clog it up and affect how well it burns. Diesel probably results in more CO being generated due to poorer combustion than lamp oil does, so be sure to provide some extra ventilation.
Take care, Lou