I visited HLM a couple weeks ago for a late Sunday dim sum (around 1PM) but just saw a short post about it on the board today, so I thought I'd describe my experience.
The place was totally packed, with lines out the door. Maybe 2 or 3 white people (including myself) in the whole place. Oddly enough, even though the clientele was so Chinese (they were calling people's tables in Cantonese) they will only have different parties share a single table if they specficially request it. If you have a group of 2 or 3, you might want to specifically indicate that you're willing to share- it will get you seated much faster.
The usual choices of different Chinese teas were provided. On to the food:
* Chicken feet were superb. HLM's chicken feet are one of the most meaty, savory, sweet, sticky, delicious dishes I've ever tasted. There was a good deal of oil in the sauce, but it didn't seem too greasy, as judged on the "how much do I want a bowl of rice with this" scale.
* Shrimp-stuffed, fried tofu in brown sauce was very good. I don't know the "real" name for this Chinatown dish. HLM's version has whole, sliced shrimp sandwiched between two pieces of soft tofu, and the whole thing is covered in tofu skin or batter or something, and fried.
* My dining companion from Hong Kong liked the crescent-shaped pastry a lot. It had a deep cinnamon/anise flavor and was equally sweet and salty, containing some mixture of meat or seafood. The texture was very good- crisp and chewy. Having somewhat more American tastes, I have to say that I like the straight-ahead salty/greasy version at Super 88 better.
* Meatballs were delicious and had an exotic, mustardy bite.
* Har gow were the weakest item. They were very fresh and had a nice vegetal flavor, but were otherwise somewhat bland.
Other things we didn't try: char siu bao, siu mai, congee, chinese broccoli, fried bread, sweet tofu, spare ribs.
As far as I'm concerned, there's no competition here between HLM and Chau Chow. HLM has much better food.