The new flavours are really good, compared to what they offered before. I have been taking this for around a year now, and along with creatine, I have seen great results. 
Goes Well With:
Soy milk.

My performance is boosted after I started using this, it can't be placebo because I figured out after workout that I done more than usual, not even thinking about it during workout. This thing and creatine is perfect if you want to improve your durability and strength. Btw it's almost tasteless, I mix it with creatine, akg and 500ml water, anyway I need to hidrate myself before workout.
Goes Well With:
Water

Really good results but unflavoured tastes awful which is expected, hold your nose while drinking it and it isn’t too bad 
Goes Well With:
Water and fasted workouts 

It says it is unflavoured but it’s tastes terrible I put it in my morning shake and it’s the only thing I can taste and smell it’s smells like old cheese mixed with sweat 
Goes Well With:
Creating mono hydrate + greens Superblend 

I am pretty sure that this is the cheapest on the market, and that it is effective. However, the taste is really bad, it really needs a flavoured version.

Although used a couple of times only, but the post workout recovery period decreased significantly. Less soreness with high intensity workout. Ready for the next workout really strong.
Goes Well With:
Whey protein isolate, BCAA's , EAA

I was not actually expected this to work but this is obviously working, I am able to see my muscles now and I can work out like a badass in the gym, I take 4 grams a day due to my weight ... it tastes horrible though, very bitter.
Goes Well With:
Protein shake.

Been reading about the bad taste of it but it truly changes the taste of anything you try to mix it with. Good side you get used to it after a few uses. The pouch though needs some fixes it can't be closed easily and the HMB is really powdery so will get all over the place.

Bought the unflavoured pouch. Words can't describe how bad this tastes and how long it lingers. The powder is so fine that even getting a scoop of it gets all over your hands, which then stink for a good 10 hours. On the plus side, I have put on significant muscle mass since taking this alongside creatine and protien powder so something is working.

Not sure why everyone complains about the taste. I've been warned that it's not the best if you get unflavoured, so I made sure I ordered summer fruits. Tastes quite good if you mix it with water or even better with any berry juice. But the best thing I discovered is when you mix summer fruits HMB with Vanilla Whey Protein + water. It simply transforms into a strawberry milkshake and tastes amazing! As for the efficiency, this stuff does improve recovery time a lot. Even if you do get the occasional DOMS after a really hard workout, the muscle pain doesn't last that long (before I would suffer from pain for days after a long workout). So it's a really good product, would definitely recommend it, just make sure to get a flavoured one if you are that sensitive to taste. Another benefit is to mix it with your protein before and after training. P.S. Be careful when opening the pouch, the stuff is quite sticky, so some of it might be trapped near the plastic zip.
Goes Well With:
Vanilla Whey Protein; Creatine Monohydrate