lapeer20m,
The type of product and volume you want to produce will dictate the mill that best suits your needs. Sawyer Rob makes some very valid points as to the capabilities of a BSM and depending on what you plan to produce, a BSM may be the best mill for your needs. Yes, there is alot log turning on a BSM and to produce straight (no crook) construction lumber. Depending on how the log behaves, you may have to saw oversize and then trim cut to final dimension. Edging on the mill requires handling material a 2nd, 3rd, or 4th+ time before it becomes a final acceptable product. Your observation and concern of the log turning involved on a BSM is well founded. Without mechanical log handling capabilities, this is a very physical task. If you are after the BEST a log can produce, you HAVE to turn the log either to deal with tension/stress and/or to get the best quality board that particular has to offer.
With a swing mill, log handling is kept to a minimum. If you don't have, or only have minimal support equipment it does make this style sawmill more desirable. Yes, a swing mill will saw ALOT of lumber in short order with only one man vs. a fully hydro. bandmill. Material handling is minimal: one pass up, one back and you have a board that is DONE and ready to load. No log turning, no flitches to reload, flip and edge again and take back off the mill AGAIN. But, you are VERY limited to your maximum cut width. And the fact the log is stationary doesn't allow to work around defects or to switch faces to get away from a defect... what you see is what you get. If you're gonna need a lot of wider boards, double cutting is an option, but its not as easy as the manufacturers make it look... it actually kinda dangerous if not done properly.
I do not agree with the kerf loss aspect. Since you can choose each dimension as you cut, waste is minimized. Yeah, a swinger has a 50%-75% wider kerf, you get that back in reduced waste that you would otherwise get in edging on a BSM. This is actually an advantage in smaller logs. BUT, if you are breaking down a bigger logs into 1x6's or beveled siding, you're gonna loose SEVERAL boards into the sawdust pile. Can you get straight lumber from a swinger, YES, but you have to approach the log breakdown completely different than you would on a BSM.
Both types of mills have advantages/disadvantages. Each type can easily outperform the other depending on the product that is desired. Sounds like you've already done some research and that is the most important part. That's the ONLY way a person can make an educated decision. Sorry for the long reply, but I wanted to offer a few more details from my personal experiences. Hope it is of some use.
BTW, the smallest Lucas can only saw 4" in a single pass (maximum depth of cut). The only way it can saw 8" is to rotate the carriage and saw 4" from the otherside so the cuts intersect. So its putting 15hp 3ph to the blade for a 4" max. cut, not 7.5 hp as mentioned earlier.