There is nothing at all wrong with ball links and connectors. IF you use good ones. There are some that use a screw to hold the ball link in the housing and to adjust the pressure on the ball. DON'T use those. The 2/56 size ball links are fine for a throttle, but take very little side load to pop the housing off the ball.

Always think 4/40 as the minimum size hardware on a gas plane. It saves a lot of heartache. It's a lot cheaper to spend a couple of extra bucks on quality hardware than to replace the entire plane after only a couple of flights.

Nelson Hobby, Dons Hobby Shop, and others market ball link hardware that used to be made by Rocket City. The Nelson part number is RCL70, and they are bullet proof. Take a look at them at nelsonhobby.com/newsite. It will take you to a site that isn't quite finished yet, but will let you into it and gather information. It may also let you order.

When you enter the site, click the heading that will take you to the main page. Scroll down to the bottom of the page and click "items of interest". When you get there, look for a topic called "customer linkage installations". You will see the linkage installed on a plane.

The stuff works great. I've been using the RCL70 linkage and others similar to it for years, and have never been let down by the hardware or linkage.