Yea, sherline lathes are quite tiny for what most people would want, I think they're just really for people wanting to do really small model engines and such, but from everything Ive seen, they really have some pretty high quality standards. Ive seen a few of thier mini lathes, but they use extruded aluminum beds for some reason, but with stuff that small, I dont think there's much to flex anyhow. A friend of mine went to thier manufacturing plant a few years ago when she was in california and got some video of the quality of stuff, and for the small lathe chucks and small stuff like that, that video really sold me on sherline stuff.
https://www.youtube.com/watch?v=5hlwY4XcNzM
I know you dont watch videos, but I figured I'd toss it up in case you were curious of the quality from a 3rd party source.
For the lathe bed length, you can never have enough length when you have a metal lathe because when you have the workpiece sticking out of the chuck, plus the tailstock length, plus a drill chuck, and a drill bit, that space doesnt ever seem to be enough. I know a friend with a 7x10, and he's always having trouble trying to drill stuff on his because the drill chuck and drills plus everything else, there's just not enough room on the lathe to drill the stuff.