I've had 2 different orders with Lazada and can tell you that the experience you have will be different depending on the 'merchant' since Lazada is just a platform.

My 1st order was a Destiny PS4 bundle at 1579. Big money, quite worried, but everything went smooth. Delivery came less than a week and nothing was wrong with the packaging. Was very happy with the purchase.

My 2nd order was with a different merchant for a PS4 game along with PS4 fans. The game was a pre-order, to be released today (18th Nov). I made this order last week, Saturday 8th.
The fans came first, along with the invoice stating the game was in the delivery. At this point I'm not super worried since I know the game is a pre-order but I sent a mail to Lazada asking if the game will come seperately. They confirmed that it will and I was content.

Then my online status says that the whole order was completed and closed and ask me to enjoy my order. When I called Lazada customer care, they checked with the merchant and now they informed me that the merchant has stated that the order has already been fulfilled. Major wtf. So I ask Lazada to give me the separate tracking number for the game (which was 179 RM). Still pending...

So I got my order yesterday, pleasant surprise! There's some serious communication breakdown between merchant and Lazada, and the fact they don't allow anything other than 4-5 star reviews is rather worrying. Still, so far my 2 experiences with them have turned out to be good. With the 50 dollar voucher I added, I got a deal that seems practically a loss ( i'm still wondering how they make money with free delivery). Worth a try.