While I was hesitant at first given the dubious nature of the first review of this product (a little research throws up some interesting contradictions - in this review he says he's desperate to gain weight while in another he seems desperate to lose it) I went ahead as it's a good price for what you seem to get.
The taste is pleasant (I normally go for Strawberry shakes, but the banana flavour they use is actually really nice for a change - didn't have to re-attune any gag reflex!) and it mixes well. I haven't quite seen the supposed weight gains, but I have definitely not seen any loss and while actual weight gains seem relatively minimal (for me anyway, but I'm not the easiest of gainers) I have definitely seen gains in how 'bulked' I at least look. This may simply be down to putting in the time in the gym but I'm not seeing any detrimental effects with this stuff.
Overall I guess this is as good as any other post-workout shake. Just beware the label isn't really in English at all. 40g servings with 300ml milk/water seem to be the way to go according to the seller's website though - I've been taking one post workout and then pre-bedtime (though aiming to get another slow-release protein for pre-bedtime instead, when I have time to get to Holland and Barrett).