Hi Dennis,
Mobile dimensional mills are fast. And fairly accurate. And for your money, it may be your best bet.
But here's my two cents from running a Woodmizer40LTHD, if that's the correct lettering. I don't have the most experience, but I've been around a number of mills.
A bandsawmill is almost certainly going to give you more accurate cuts. If it's tuned right, you can almost guarentee 1/16" accuracy, and often achieve much greater. The finish can be smoother, too, but you'll want to consider what species you'll be milling for which mill. An example: Sitka spruce, with the longest wood fibers on Earth, is not easy with a bandsaw mill, since the blade want to wander. Bandsaws are more suited for hardwoods, but can do alright in softwoods, too.
And your resawing potential is much greater than a mobile dimension. All those slabs can be milled down for 1X or whatever size of siding you choose. I've millled down to clear 1X2 and even 1/4" sticker stock. Bandsaws are much more efficient, hence the name of Woodmizer.
If you're thinking of timberframing with unplanned beams, the quality from a bandsaw mill is likely what you want. But then again, I've seen some beautifully dimensional and square mobile dimensional wood--but it's the exception, not the norm
Bandsaws and blades are a lot more finicky. If your blade is dull or set wrong, you're shut down. And you'll be changing blade a lot more often. But sharpenning and setting isn't that bad, if you don't mind the futzing work.
All this said, I've know two Woodmizer nuts who converted to Lucas Mills. You can take them anywhere, including deep into the forest. I don't have any experience with them, but boy do they have a following.
It's like building a house. Lots of ways, lots of tradeoffs, but one way is most right for you.
Good luck.
Zach
