Unfamiliar with the quality of these dolls, I initially both just one (Zayn). I was satisfied with the quality. I decided to get two more. Zayn was already out of the box when I thought of making this review.
The singing dolls come in two waves. I don't know how they are called officially but the distinguishing feature of each is the packaging. One comes in predominantly red, while the other in white. Zayn and Louis (above) came from the same wave. I read somewhere that the dolls in white boxes are called the "concert series". There wasn't enough info online about those in the red boxes. I grabbed this online pics showing the complete set for each series.
I don't care much for the music playing feature of the dolls. I bought these dolls mainly for their clothes. Zayn's is my favorite. It offers more mix-and-matching opportunities. Louis' is very youthful while Liam's is very basic. Liam with the vest (above) is available but I don't like vests. The clothes uses velcro for closure. They all fit Ken dolls. The white boxed dolls were replicas of the attires from the photo below (not mine).
The clothes generally have better quality compared to Ken's. The collar is clean, unlike Ken's. The lapel on Zayn's suit also shows more effort although it adds bulk.
The sleeves on Louis' shirt are lined, probably to prevent staining. There was still staining, though.
Liam's pants weren't as well-crafted. They seem to fit nicely but with the help of some stitches behind the knees to keep it from looking loose. Also, I don't know how something so faded can leave so much stain.
The dolls have ample articulation. The hip joints seem too tight. I felt that I was breaking them when I tried to spread their legs apart. It will take more effort to put them in naughty poses. The 1D joints may seem unsightly basing on today's standard but these are simply a lot better than the newer statue-like Ken dolls. They have holes on their abs for the music and their belly button acts as the trigger to play the music. They have a switch on the side of the torso to turn off the music player. It's an important feature as the poorly recorded music can get annoying for non-fans.
One common critique on these dolls is about their faces. They don't look like the celebrities they represent. Zayn, the most good looking from the group for me, looks too sad and old as a doll. I like this doll's face the least.
Liam's face (the doll) is quirky or creepy. I kinda like it. Dolls usually have either a poker face, a smug smile or a toothy smile. A tight-lipped smile gives opportunity to a different character.
Of the group, I like the real Louis' face the least but I can't say the same for the doll. The doll's smile is just warm or naughty, depending, of course, on the eyes of the beholder.
They may not be the best dolls ever. What makes them beautiful are not the faces nor the singing. (The band member look a lot different now from the time these dolls were based on.) Fans who want's them forever young, may not need any convincing in buying these dolls. Non-1D fans like me might find it hard to pay for these dolls for over US$18 but at that price they are better alternatives to Ken statue dolls at the same price. For one thing, their clothes are better crafted.
I wouldn't suggest buying these as an investment. If they will be indeed that popular in the future, better doll versions will come out. I've seen kids doing reviews of the boxed dolls on Youtube. They should heed what their idols suggest: live while they're young. To those keeping them in boxes, you and I should happily enjoy the moments and play with them right now!