Just wondering has anyone had any experience or got any opinions on preformed loops on fly lines?

I'm currently using a Rio Grande line with a factory made loop on the end, to this I attach a Rio tapered leader with a perfection loop on the end using a loop to loop connection. For some reason I'm having doubts about this setup and am considering cutting the loop off and needle knotting the leader to the line.

I have a feeling this may produce a better energy transfer from line to leader.

Any thoughts? Thanks

Dan