Trying to decide. Found some 1/16 and 1/8 weighted screw locks. Need to decide if 4/0 or 5/0 will be better?

I use 7/0 3/8oz for 4.5, 5, and 6" speed shads, which is the Bass Pro clone. Its a little big for the 4.5, but its perfect for the 5 and 6, and it lets me throw all three on my swimbait rod. Hope this helps. GO CATS

I would not go any smaller than a 5/0

I use min 6/0 1/4 on something that size but don't really throw anything that small all too often.

I use the 8/0 3/8th on the 5.8 and it is not oversized/over matched at all by the terminal tackle at all.

Keitech recommends a 4/0.  I was doubtful at first, but a 2/0 ended up working very well on the 3.8" ones I fish the most   

 

 

I have used both with no difference at all.

I use a 4/0 for the 4.8

I use a 4/0 Owner Beast and a 5/0 Owner Twistlock, sooo... both?

I use both. 

Either.  Hook sizes are not the same across brands, so either should work.  I use 4/0 Eagle Claws or 5/0 Owners on S.I.F.s

I use a 3/0 but mostly a 4/0 for 3.8 and 5/0 for 4.3.