I have the Mafell beam saw with the carbide chain and it does cut clean. I have never really tried to do curves with it though. I imagine it would work well for a large radius. It does require a bit more effort to do a rip cut, but not too bad.
I have an Oliver bandsaw that suffices for most large curved work. Smaller braces etc. end up on the stationary bandsaw.

OMG. I learned 2 things tonight. Timbeal, the jig is AWESOME! and we have a cruck job coming up, wonder if one of our mills is that manly to cut freehand on the mill. Love it!

What are you running for a mill? Does is raise under power or is it cranked? It is tricky to get the feed and lift/drop feeding at just the right times. Cutting down into the curve is easier due to the back of the band resting on the kerf but raising out of the cut can be tricky because the teeth are leading the cut and it just want to cut straighish so the blade gets put into more stress. I try to position the log so most of the cut is a drop and the last is nearer straight/level. I do this by raising the end at which the saw enters which us always the big butt end. They can be left with the band sawn look or a slight hewing job to clean the sweep up.

Timbeal, It's a crank. so cool!
still tuning up my mill, haven't had much time to play with it.
dave

Found one:

Nice! SCMI is some good stuff.

Wouldn't it be more efficient and economical to lease a Falberg Titan. Falbergsaws.com has a new website coming out ( being pubished right now) with details about the new leasing option for portable bandsaws the average timber framer can afford without taking out a second mortgage. Cutting Arches? This is how easy that works [ https://www.youtube.com/watch?v=nsyOWfMfxdM ]

falbergsawco@skybeam.com