I think it's important to look at the history of primary school- if not all testing in UK state education. When I went through many moons ago, it was entirely possible to go from 4 to 16 with the 11+ as the only form of public exam you ever sat. You could basically fail every step of the way and no one KNEW til you were 16 and got one grade 5 CSE. OK, this was also back in the days before primary reports, homework or parents evenings, too, so a parent had no way of gauging their DC's progress.
At secondary, as happened at my DBs SM, every parents evening was a continuum of 'X is doing fine' right up until his CSEs then SUDDENLY 'We don't know WHAT'S gone wrong, he's stopped working/concentrating/started mucking around'.. and X fails. BUT funnily enough EVERY parent my parents knew from that school had EXACTLY the same experience- wildly successful Y7-10, then a lamentable failure on the part of the DC in Y11. Funny, that...mm.
Now, I think SATS are badly misused. But the answer is surely to ban the state wide publication of results, ie league tables. THEY'RE the problem, not testing, per se.
Fwiw, I like to have a quantifiable measure of my DSs strengths and weaknesses and I think it's good that the school's overall standards and, importantly, value adding are scrutinised somewhere along the line.
Finally, I wonder what alternative those who want to abolish SATS would come up with? I mean, in this day and age, we ALL want to be informed every step of the way of every nuance of our DC's progress, don't we, and I believe I read somewhere that the teachers in Wales who have abandoned SATS are up to their eyeballs setting, marking and analysing the alternative! Be careful what you wish for....!
So though I think Balls is a twat, I'm not anti SATS.