The only thing I'll use those ez connectors on is throttle and I hate them even then.

Z bends are great for not coming loose but do have slop. Fine for trainers and such.

Ball links are not something I'd ever use on a control surface. I've done so before and had wear issues right from the start.

There are many ball socket types out there and some are good and others not so much.

Steel Pin Clevis is what I prefer in most cases. Tetra Clevis are the best.

There are some very good linkages from Central Hobbies that I love but they're pretty expensive.

The dual Axis rod end is great.
http://www.centralhobbies.com/contro...age/link00.htm