In general, the above article is a fair assessment of the history and politics of Militant/SP.
But what it doesn't mention is the class nature of the SP's base, and that is important. I only have my own impressions on which to base this judgement, but as an experienced observer of these things, my estimate is that the SP is alone on the British far left in having a predominantly working-class make up.
Yes, I know that this is not decisive. 30 years on the far left have taught me that political ideas outweigh sociological composition or weight of numbers. But it cannot be insignificant that the SP recruits workers, on a scale that no other Trot group currently can touch. I include the AWL in that stipulation.
Trotsky somewhere uses a phrase - can't remember the exact reference -about the importance of 'smelling of the workers' whisky'. The thing that strikes me more and more about the SWP is that it smells of the university seminar room and the academic journal. The SP, whatever the deficiencies of its ideas - and its 'theoretical' output is weak - is noticeably more proletarian and less ex-studenty.
It's members are also simply nicer human beings. Although they are deferential to their group's received wisdom, they are not as robotic as goodthinkful SWPers. They know how to operate as citizens of the labour movement, in sharp contrast to some SWP I have observed in my own union branch. Sometimes civil conversation about political differences is possible.
And as Marxists believe that the emancipation of the working class is the act of the working class itself, I will freely admit to a grudging respect for the SP. So wrong on so many issues, but still ...