Seeking reliable z-wave plus US mini-plug outlet

What issues are these?

The only issue that I had with mine was that it would only communicate at 9.6 kbps, even though it was a zwave+ device.

There is an antenna modification described for these devices (to expose the internal antenna) that apparently makes a dramatic difference. @kkossev described it in this post:

I noticed that adding an external antenna to my C-7 Hubitat also made a huge difference. My unmodified NEO CoolCam plugs now connect at 100 kbps and are very responsive. The plug below, which used to connect only at 9.6 kbps, now connects at 100 kbps .....

So before you purchase new plugs, you might consider the antenna mod described by @kkossev, or adding an external z-wave antenna to your Hubitat.