I have two and one on order. I have cow and giraffe, waiting on a tiger, and DD loves them. I think they are my favourite day nappy tbh. Not sure they would last overnight with my big heavy wetter. They are bigger than the LL OSFA which do not do up around her thighs, not sure how they would be on a wee bum. Have had big wee's and poos too, including squitty teething ones, and only one leak, when she was being 'watched' by her Daddy. Every nappy will leak if it has too much wetness!
They are an amazing price, but are very good quality, the stitching, poppas and fabrics are quality, and it is a good size. The fleece keeps bum nice and dry, and you can boost it as needed. It comes with one microfibre insert, like the LL one.
The potential problems are, if you are very 'ethical thinking', then they are probably made by a poorly paid young person living in poverty. As are many things we buy, unfortunately. Also resale value would possibly be lower than with other more recognised brands, but the cute prints may counterbalance this. Besides you buy a nappy to use it firstly, and at £4, it will not owe you much. It is also coming a long way, and takes a few weeks to arrive. This suits me as I buy less. I allow myself to order one once I receive one. Daft I know.
For you personally, it will not 'add' anything in particular to your collection as very similar to the LL, and if money is tight, I would consider buying some two part bamboo nappies for nights. However, 8 daytime nappies are not likely to be enough for a newborn, so if you like the pockets you have, you could supplement with the Alvas. Make sure you get version 3 as they are a more generous cut.
They are sold under different brand names, and by UK buyers at inflated prices. I think once the brand is more accepted, prices will indeed go up.