Gary,
I agree if the connector is miss match and get poor contact.
But I'm talking about the servo extension are made to fit exact connector to the servo brand.
At my shop. We had built many jets and install thoundsand of servo extension. We only use 22g and gold plated connector.
We had no problem with poor contact if install correctly.
From my experience. I find some of the use servo extension had poor contact. I guess it been plug-in and unplug so many time the pin got expanded. This apply to any brand.
I do run to some bad servo extension from the brand I use. But it is very easy to detected if pay attention to the wire. When you push the connector in.
If one of the wire are pushing out. That mean it connector pin is bad. That when you get the poor contact.

Like I said. Check your installation carefully. Any good servo extension do had bad one. This doesn't mean because of the brand name you choose won't get bad one.
Remember. All the servo extension was made oversea. There are made in mass quanity. No manufactor go to check one by one.
I saw how is made from one of the factory I visit.

My own opinion. I always shop for best products and right price for my customer.
Tam