An easy comparison to make, but again if we were to prioritise strategy (rather than what feels right) we wouldn't just go for that comparison and then bypass further thought about it. We would examine what worked about the South Africa boycotts, what didn't work, what the differences are between the position of South Africa and the position of Israel, economically and politically, the differences between the balance of forces within the two countries, the cultural/media reactions to external actions within those countries and so on.
The point of a political campaign is to win, not to feel good, and I think the pro-Palestine campaign in the UK has no strategy by which it can actually effect any change whatsoever within Israel or Palestine. In the meantime the campaign is waged with such lack of subtlety or political thought that the almost constant stream of 'accidental' anti-semitic speech it produces (and I know that to be real from experience and the experience of friends in the Labour Party) became the stick with which the right wing media could help destroy the party.
Added to that neither I nor many Jewish people in the UK nor in Israel can see why the UK left should be so obsessed with Israel compared to, say, Saudi Arabia, whose violence has been significantly greater over the last few years and which 'we' as the UK are much more implicated in.
When I add up all that on a balance sheet I reach the conclusion that I've stated here before: the left in the UK would do itself a favour by shutting up about Israel except where discussing it within broader foreign policy objectives - and I do not think the Palestinian people would suffer a single disadvantage from their reduced chatter on the topic.