Not necissarily. At least not anymore. New stuff is coming out everyday. If you look at the new XM-L lamps for instance, which put out 100 lumens per what. You won't find a 1 watt led that puts out 100 lumens. They are 20% more efficient than the XP-G's which were an improvement over the XR series. So the technology keeps improving. But when comparing a lot of manufactured fixtures out there at this point then yes.. The ability of 1 watt leds to penetrate very deep in the water is an issue as you touched upon as well. So generally speaking, comparing a 3 watt fixture to halides or T5, I think the leds still come out ahead. More and more so every day.
Agree!!! How could 1w LEDs be more efficient??? You'd have to run more 1w to equal a 3w and the new generation LEDs are quite efficient.