Yet another "Silky" vote. I have several models. The go-to is the Sugoi - especially for what you are describing. It isn't fun to cut 10" diameter pieces, but it is do-able. 6" and down is nothing. I will say though, that live wood cuts a lot easier than dead. I don't think I'd want to cut many 10" pieces of dead hardwood. A good quality woodworking saw may be a better fit there.
If you watch on Amazon, you might find the Silky saws as much as 40-50% off other retailers...not sure why/how, but that is what I have found. I bought replacement blades for my Tsurugi for $16. I ordered 3 then went back to post the link and gloat a little, but they were back up to $43 each...
I have used Samurai brand as well. Out of the box, it was pretty good, but dulled very quickly compared to the Silky. Corona, Fanno, ARS aren't bad saws, but they just aren't as good as Silky. I have a Marvin that I use a bit around the house here and there, and it is very good. I haven't used it enough to comment on its longevity, but the fact that Marvin's website sells Silky is a little telling...