The major benefits I have found with swing blade mills are:
Faster sharpening and blade life between change outs. With most swing blade mills you can re-sharpen/tune the blade without removing the blade. Typical resharpen times are around 2-3 minutes.
I saw a lot of reclaimed and partial damaged/rotten/checked logs. With a swing blade mill you have a lot more versatility in cutting around unwanted portions. This allows me to use a lot of logs that are normally considered worthless.
Less turning of logs. with a swing blade mill you cut both vertically and horizontally, in doing this you dont ever need to turn or move the log. For example if you want to cut a 2x6 you cut down the log 6" deep and then turn the head and cut the 2" side cut on the return pass. With a band saw you have to cut slabs and then turn them on end to make the opposing cut. The only time I ever turn logs is if I want to cut a very large timber over 8.5"x17" or large tabletops. I regularly cut 8x8 and 8x16 timbers. I have also cut timbers as large as 16"x24".
More Consistency in sizes. Using the "setworks" most mills use you can quickly easily cut of 2x6 lumber accurately and fast.
Straighter Cuts. Swing blades mills typically make straighter cuts, this is partly due to the ease of sharpening so you always keep your blade sharp. With blade mills you often make smaller width and depths cuts this makes them straighter as well.
Inexpensive maintenance. I have only purchased 5 blades with my mill and have cut in excess of 80k board feet. I did have a learning curve and ruined several blades in my own operator ignorance. Consistent
water cooling is key, lock your logs down well and dont try to cut to fast when your in difficult
wood.
I found the brand X mill to be excellent. I looked at the lucas and peterson mills as well but after talking to with brand x and getting a demo at their shop I purchased
local(the are built in MT!)
The only disadvantages I have found are larger kerfs or 1/4" if you are cutting a lot of 1" boards this can be costly. I mostly cut large timbers for my timber frame business so this was not an issue for me. The other disadvantages is cutting width with an 21" blade your are limited to 17" wide boards if you cut from both sides. If you only want to cut wide planks for tables or furniture buy a bandmill. I get around this by using a chainsaw for a finish cut or I flip the log over and saw down from the other side till I get the thickness I want, this has worked great for me.
The lucas and peterson mills are designed to be extremely portable keep this in mind when considering. They were designed to take the mill to the log, not the log to the mill.
I found the brand X, which is stationary to be much more stable and better suited for my log
yard.
Here are a few links on swingblade mills.
http://www.brandxsawmills.com/video%20request.htm http://www.lucasmill.com/ http://www.petersonsawmills.com/index.php Great videos are available
online search around. By far the best way to learn how they work.
http://www.petersonsawmills.com/mill_ops_video_index.htm http://www.google.com/search?q=lucas+mill&rls=com.microsoft:en-us:IE-SearchBox&oe=UTF-8&rlz=1I7GGLL_en&um=1&ie=UTF-8&tbo=u&tbs=vid:1&source=og&sa=N&hl=en&tab=wv If you guys have any other questions let me know and I will answer them as best I can.