what connectors do you use on your jumpers?

I'm using spades to spades on my main wire and non locking bananas on both ends of my jumpers. I think the low end suffers from using the bananas. The cable maker doesn't offer locking bananas.

I want to get spade to spade jumpers but I have always been hesitant of putting two spades on top of one another. Is this OK or is a banana to spade jumper preferred?