I have both in cast offset. In northern Minnesota after spending a day chopping in fall traps along frozen logging trails I sure appreciate a smaller hole to make for the 550. The 550 isn’t letting anything out if it hits the pan in good order.
Bigger in a bigger bed or smaller in a smaller bed packing is the key. Wether Pete moss, waxed dirt, ant hole sand etc keeping the bed relatively dry is important. Sometimes you just have to dig em out and re set.
The pipe dream type sets are nice as you have that heavy grass/hay/ mulch over top that helps keep th trap working.
For a young person consider cost. More sets, better odds. Don’t get any more for your fur if it’s caught in an expensive trap.
As for my 650’s there is a two piece setter device made by a guy over on Trapperman. They are slick and easy to use plus a lock-ing feature for safety.

Osky


A woman's heart is the hardest rock the Almighty has put on this earth and I can find no sign on it.