We went here at the recommendation of our local wine shop back in London. It was a bit hard to find - it's inside a hotel and the easiest way to get there involves a 20 minute train out of Lisbon and then a ten minute walk along a narrow pavement next to a dual carriageway. Thankfully cabs are cheap in Lisbon so it was easy to get one back into town (circa €15).
Nevertheless we were very pleased with our decision to trek out. They have a lovely view of the river (probably better at lunchtime - not too much to see in the dark).
The tasting menu with matched wines was a hit. Every course was interesting and the wine pairings (all Portuguese wines) were fun and a different, but very well matched. The sommelier was very knowledgeable and we had a good chat about Portuguese wine - his English is great. He said he is studying for his Master Sommelier award, which is insanely difficult (watch the movie Somm - it's on Netflix). Very impressive!
The atmosphere was a bit lacking - we were the only couple in there that evening, and as mentioned the journey out was a bit trying. But otherwise a perfectly lovely evening. Recommended.