I have the
t-kingdom : 1700 long shirt and I am around D size / 34". I got the
medium size and it was around £50 (UK here). Came after about 1-2 weeks, and at first I was thrilled... And then a little disappointed. I am large, but for that price I expected a miracle let's be honest

I'm a student so that kind of ££ is loooads to me, in fact it's the 2nd most expensive thing I've ever bought myself (the first being my DM's which I was and am far more happy with

).
Anyway I have had it for let's say 8 months now, and the non Velcro side has split stitches at a point, which I should really sew up. I never go out without it on, but the job it does is marginal on me.
Binding:I put it on and try to squish them to the sides, where it binds best, but the problem is a very large gap between the boobs where they eventually come back together to create THE MONOBOOB, which is ugly and horrible. When they are to the side I get sideboob which then allows the fabric to dig in underneath my arms and make that area sore. I find I have to adjust the boobs back to the side whenever I get the chance, annoying because the shirt must be tucked into trousers.
Rigidity/ Longevity: I find that below the boobs, the compression fabric flips up due to bending which is uncomfortable (the binder has now many dents in it from places where I bend and it has 'memorized' that, and will not go back to being nice and flat. When it's off me it has many folds and bumps in it that do not go away with washing). It has also discoloured to be a bit grey/ yellow in some places which again does not go away with washing... I am loathe to wash it since the mediocre job it does will only become more mediocre. On several occasions, when I have been out, the Velcro has just given up and the whole thing has come undone- MOST annoying and embarrassing. This is the only size for me, if it were any bigger it would just not bind, and I would not fit in it if it were any smaller.
Comfort: At first I thought it felt like a long hug, but now after just an hour I find that my back aches, my ribs ache (the compression fabric encompasses the ribs and you cannot breathe fully), after I eat I get reflux (I have acid reflux so this is not inherent in the item, I assume) and as stated, I cannot run very well or strain myself because fluid will build up in the lungs where you cannot breath properly- also the original discomfort only doubles when doing this. I have had to sleep in it on occasion... Sometimes for more than one day at a time, I suppose only lending to it's lack of binding. But those were the most uncomfortable nights ever and when I could finally get it off it felt like heaven... I just can't let them be 'free' so it's binder or my crappy 'home' bra.
Overall: For large sizes, this is mediocre at best. For someone smaller than me, C and below, or under 34" I am almost 100% sure this would work a charm (but probably still be uncomfortable). As it is, size D and 34" there is just nowhere for them to go within the item where they will stay until they reach monoboob... It's the friend I hate but have to go out with all the time
When my birthday comes up I will be searching for an Underworks binder and hopefully something better... It makes me very upset that my binder does not really work and often stops me from going out because I just don't feel like wearing it and going through with the discomfort.