Well, here's my answer.
Use them all. You will decide as you use them which does what you are trying to do the best.
Personally I like lots of room under the arch and around the needle. Modern type squarish machines, or those with the two piece plastic bodies are not even on my list of machines to use.
As for the motor on the 221 .... lube it properly and keep the belt adjusted and it's gonna be fine. That is not a week kneed motor.
Joe