I'm just gonna go straight to it and say that Hai Di Lao probably has the absolute BEST mala huoguo i've had in my life. I generally don't like eating hotpot in singapore or malahuoguo for that matter based on two things, its too hot here and the hotpot usually sucks. So yes, I actually am biased against hotpot at all times but I am incredibly glad that I went to this place. Firstly, the restaurant is very modern, with great air conditioning and facilities. Also the ventilation is great so at no point will there be steam coating your face in spicy sweat which was something I always found unappealing about eating malahuoguo in singapore.
Now onto the food...it was absolutely awesome and I dont say this lightly as I rarely ever rave about food to such a degree. This is mostly because of two things fundamental to a good hotpot...the stock and the sauce both of which haidilao stock in abundance and quality. The yin yang hotpot was tastier than the 2nd best malahuoguo ive had by an order of several magnitudes and it wasn't MSG. They actually bother to boil the stock for the soup so that it is genuinely tasty and full of flavor. Next up is the sauce, the place has a selection of something like 20 different sauces (if not more) and all of them are delicious. The zimajiang was thick and flavoursome unlike the watery nonsense you might get at a $15 all you can eat hotpot at geylang or a similar venue. So feel free to mix and match till you create the ideal dipping concoction. The stock and sauce is so good that you don't even need good quality ingredients for a great malahuoguo experience, but luckily haidilao also has very good quality ingredients, the meat, tofu, vegetables etc were all good at the very least. No bad dishes.
Now onto the bad points, this place is EXPENSIVE, I spent about $50 a head between myself and a friend and although we did order a decent amount, it was no where a huge amount. Although the price may drop with bigger group I would say youll be paying at least $35 a head at the very least if you want the full malahuoguo dining experience. The service isn't superb but frankly, who cares about top class service when eating hotpot anyways.
For abit of perspective, I have had the real malahuoguo in China and taipei and many other countries for that matter. I've even had the haidilao in shanghai itself (its a chain) but I suspect due to the quality control of singapore, the chain here is much better. So if youre willing to fork out abit for a divine malahuoguo experience then hai di lao is the place for you.