I have never had to change my tension on my machine.
It has a top loading bobbin and no problems there either.
I quilt all my quilts on my Viking Sapphire and have no problem except when I dont thread it right. It is so easy to wind bobbins while in the middle of sewing without unthreading, and drop it back in without lifting my table insert.
Ive been sold on drop in bobbins since I started sewing many yrs ago on a Singer.