i use both,but like the 3/16 more than the 1/8th. in some wood if it is grainy i dont like using the 1/8 because i think it gets caught in between the grain and grabs the grain and veers off center. the 3/16 is less likely to do that. also 1/16th inch wire doubled up is a little hard to get in the 1/8 whole especially with the use of a grommet that makes the whole a tiny bit smaller.
thats what i think.
