Yes there is a difference in quality between high priced US made connects and the cheap imported connects. But is the difference worth it? At first, I thought so, and only bought the quality US connects. Now I realize it's far cheaper to change the connects once or twice than spend the bigger bucks for the higher quality parts.
At first I felt kinda crappy about sending more money for cheap Chinese parts, knowing that maybe US jobs are being lost because of me and people like me. But, the reality set in that I can't keep raising prices to cover the fast growing increases for everything I buy, including fuel, so somewhere I had to draw the line and hold my costs down in order to keep my pricing level.
I'm sorry if I cost any of my US brothers their jobs, but I gotta live too, and I succumbed to the hipocrisy of buying certain lower cost imported parts while still waving my US Flag.
Now when it comes to the more mission critical items, I do not buy the cheap imports or knockoffs, but rather stick to quality oem parts.
Relating to lubricating the connects, a good silicon spray works very well, and doesn't tend to get gummy or cause too much dirt to collect.
More often than not, what really causes the connects to fail is impacting them on hard surfaces (ie concrete), which knocks them out of round. Usually for me the plugs wear out first, and don't fit well in the coupler, so often I can just change the plug and all is well.