Looked up some of the details.

Essential Pro is a 70/3 thread -- meaning it is 70wt, 3-ply. I assume the 3-ply means that it is manufactured as a multi-filament polyester thread.

So Fine! comes in both 40wt and 50wt, both of which would be heavier than Essential Pro. It is a multi-filament polyester thread.

Bottom Line is 60/2 multi-filament polyester thread, which makes it finer than either of the So Fine! weights.

Glide is a 40wt trilobal polyester thread, which makes it heavier than all of the above. Although the Superior Threads trilobal polyester threads are not as strong as their multi-filament polyesters, my experience is that Glide is stronger than all of the Superior Threads listed above, whether multi-filament or trilobal.

Here is a Superior Threads article that describes its different types of polyester thread:
http://www.superiorthreads.com/polyester-thread/

I love it on my very old HQ16 exclusively. I LOVE it and the great price. I use prewound bottomline bobbins as I do not have a bobbin winder. I have not tried it for piecing as I have lots of that type of thread.

I use it in my Bailey all the time. It's good thread, nice and thin but strong, and the price is right. I haven't had any trouble with it at all.

I use it on my Gammill, top and bobbin and like it. Have no tension or breakage problems with it.

Great! Thank you all so much for the feedback! I actually even really like the cotton essential threads but I really only use cotton for piecing...I'm going to place an order!

I have all the various threads from Connecting Threads and have had no problems whatsoever. One thing about the Essential Pro as its polyester is that it does not break easily. Low lint too. As someone else mentioned though they don't have as many colors to choose from though. I use Ct's threads for most all my quilting though and like that they have lots of colors to choose from and their price is great. I tend to order when they're having a sale on their threads and keep lots on hand. If they have the same color in the their larger cone variety I tend to order it instead.

That is all I have ever used. I think it works great.

I love it too. The one thread that works well consistently on my Avante. Rarely ever does stupid things!

I've even used it in my emb machine without any issues. When ever I have a problem with a thread I either put it behind the machine in a cup or change my needle to a different size and type if needed but I get it to work. I spent way too much money on a top of the line machine to have it be finiky with what thread I want to feed it. That was one thing that I liked about my new serger, it likes all threads, even with different weights. I could of bought a car with what I spent on just those two machines so I'd better be the one in charge, not them. They are also both self adjusting when it comes to the tension too, even though they are both a different brand. I do have to agree with the ones saying sticking to cotton for piecing, I agree, cotton thread goes with cotton fabric, doesn't cut thru the fibers after a while. If its something that I already know won't be around for the long haul, anything is game as long as I get the look I want