Depends.
If I'm cutting in the woods, a small tooth 021 and 357 with 18" bar. If I'm cutting on the log deck, the 357, or now a 661 w/25" bar.
357 was my go to saw for seven years. It was down most of last year, and after the first several weeks, I needed a saw to use... and switched back to Stihl. I bought and ran the 661 all year, with the 357 in and out of shops and on the shelf since mid June.
It is on the shelf now, supposedly fixed, leaking bar oil all over, which it never did before. I took it back for that because you can't set it anywhere without making a mess. Everywhere I set it down, sticky, tacky, bar oil. On the SS table, on the bench, on the floor, in the van, riding home from the shop. Replaced a flippy breather thing in the oiler, but still leaks pools of oil. Not impressed. Not positively anyway. Still leaking...
We'll see...The "good saw for seven years" might be the end of story. I don't need useless junk sitting on the shelf. I don't have many shelves... for a reason. We'll see... if it's still there, or not, this June.
Is the 661 heavy? Not if it's sharp.