Rated 4 out of 5 stars

Given Maxime RF's very prompt reply and the promising note that it bears, I'll say Thank You to Maxime and will increase my rating to 4.

Regarding what I previously said about the additional features of this add-on, they'll remain of no interest to me, but if this add-on's present problem with continuing to buffer videos when I've selected the option for stopping autoplay gets corrected in the next version of this add-on, then I'll have the add-on still installed and it'll be updated. At that time the add-on will be re-enabled to give it the "stop autoplay" test again.

On a last note, why not change the options. F.e., there could be two options and the second would possibly be activated only if the first one is selected. The first would be for a user to select whether he/she wants to prevent videos from autoplaying. If the person sets the option for stopping autoplay, then the additional option would be to have the user indicate whether or not videos should be buffered. This would permit users to use both of these options according to whatever combination a person prefers. F.e., I'd choose to stop autoplay as well as for there to be NO buffering.

That would leave far more complete control in the hands of each user; for some, perhaps many, users would prefer no autoplaying as well as no buffering when a video isn't playing. This way, people with slow and others with sufficiently fast connections would both be able to benefit.

Oh, and why can't HD videos be prevented from buffering when the videos aren't being played?

This review is for a previous version of the add-on (1.5.1-signed). 

Hey Michel,
I will try to implement a "Stop buffering" option like you have suggested, but for now there is no way to use the YouTube API to stop buffering... The first idea that comes to me is to unload the video and replace it with one of its thumbnails, then load the video when the thumbnail is clicked... Maybe it will do the trick.
If you have questions or suggestions you can contact me via email.

Stopping autoplay of videos is the most essential thing to provide Rated 3 out of 5 stars

There's a problem with this add-on and it's that when I want an add-on to prevent YouTube videos or videos at any other website from playing, it doesn't mean that I want there to be any buffering. I have no need for the buffering. Instead, I need for videos to simply not automatically play. I have a monthly 35GB of Internet usage at no additional cost, but will have to pay for all additional usage and buffering videos increases this usage. Having many tabs open while using both Tab Mix Plus and Session Manager add-ons, plenty of the tabs can be for YouTube video pages, so imagine if everyone of those pages buffers the videos, then I'll exceed my monthly 35GB fairly quickly; given the number of videos that I watch nearly every month.

To prevent autoplay is the sole functionality I really wanted to try out Tube Enhancer Plus, while also being willing to check out the other features the add-on provides. Having done that, I have absolutely no need for those additional features. If I want them, then I can just download a video and watch it in a good and free video or media player.

Stopping autoplay is all I'm seeking and, yes, I had read about Tube Enhancer Plus's buffering even when a video isn't being played but also hoped that this wouldn't be too bad. It is. It's buffering entire videos before I click Play.

I uninstalled Stop Autoplay due to thinking that it wasn't helping with the current version of Firefox, but it wasn't. So videos would begin to autoplay. But, if I clicked to pause, then a little buffering continued to happen. It wasn't much though; far from complete videos, even short videos.

This add-on is of very little practical usefulness for anyone who has an Internet speed of 500Kpbs or faster, and probably even lower than 500Kbps. Mine is 5Mbps, and my limitation without needing to pay more is 35GB data transfer (up and down), so a true autoplay stopper is what's needed. Sorry, but the other "bells and whistles" of this add-on aren't of sufficient practical value.

This review is for a previous version of the add-on (1.5.1-signed). 

Hi Michel,
Thank you for reporting this issue... It seems that YouTube has changed something, this is why videos keep buffering even if the selected format is not HD. I will try to fix this in the next version.