Very often I find that it isn't the ASL thats the problem, its the short lane leading to it. Very often they're VERY short, no more than a cars length, they seem to assume that the cyclist will be right by the kerb to begin with and that they can be funneled out in front of the traffic, requiring a rather sudden change in direction. Personally, I'd prefer no cycle lane linking to the ASL, I'd rather not have motorists encouraged to believe that we should only be filtering on the left (and moving over to block me filtering on the right, which is obviously better when you're turning that way!).