In a former life, I used to know a lot about stock control in fashion. Stock control is how fashion retailers make money. Its all about not having lots of stock left over that you have to discount; discounting destroys profits margins and it destroys your brand. So this means that you have to make hard choices about your manufacturing base. You can make your clothes in cheaper manufacturing countries that are further away, and therefore take longer to get here. If you do this, you are not going to be able to get the latest designs to the shops a few weeks after Fashion Week. Or you can make your clothes in more expensive closer countries, meaning that they are more on trend. This also means that you don't have to order all your clothes at once; if they don't take too long to get into the shops you can see how well they doing, and then order more of them if they are popular. This is the route of Zara which changed fashion retailing when it came to the UK. Very tight stock control means it doesn't have to discount too much, so can actually sell things fairly cheaply without destroying its profit margins. So if you see something you like in Zara or H&M, you should buy it quickly. It might not be there in a fortnight.
Uniqlo manufactures in China, which means that it's cheap, and the stock doesn't vary too much from year to year. They add a fashionable cut or line, but on the whole they deal with the basics. This means that they are not taking huge risks with making something far out there, which doesn't actually sell. A good place for tights you might think. Retailers who are making the same product year in and year out should have it sorted.
My previous purchases at Uniqlo have been their thermal tops, which have been cheap and warm. I was confused by the fact that my tights are neither. These are £4.50 for one pair. I don't know what justifies that. According to the pack they are 92% polyamide and 80 Denier but they don't feel like it - as I say not quite warm enough. In terms of comfort and fit, they are alright. Nothing to mark them up or down on. They don't have a label or anything to mark which was is front or back, so do fall down on that. Overall, nothing to differentiate them from Debenhams or M&S apart from the fact they are more expensive.