At first glance of course, it makes a lot of sense that, if English MPs cannot have a say on Scottish education, health, law and order, etc, etc, why on Earth would Scottish MPs be allowed a say on English education, health, law and order, etc. The current system is an insult. (However, as Iain points out, pre-1999, when everything was decided in Westminster, many laws were forced on Scotland by English MPs who had no interest in Scottish Law.
As Iain points out there is more to it than that. And his piece shows once again why we are would be so much better as two friendly nations enjoying good relations but with separate government in the style of Scandinavia. We are quite simply too different to be one country.
An English grand committee/parliament dominated by Conservatives, could overrule a Labour UK administration, dependent for its votes on Scottish and Welsh MPs, rendering a Labour manifesto even more of a piece of fiction than at present.
At present Scottish MPs can, as with Welsh and Irish MPs, vote on every matter. In fact all SNP MPs only vote when finances which translate to Barnett Consequentials are involved. Other parties may vote on more. I have no idea.
An obvious problem about removing this right is that Scots MPs would no longer have any say in the amount of money being spent in England (not their business), but by consequence, how much was to be given to Scotland.
Of course it would also make a two-tier parliamentary system with some MPs entitled to vote on everything and some not. Surely that would, or should, involve a different set of terms and conditions, salary and status.
Of course the whole thing has been a dog's dinner since it was set up with the express intent of making the Scottish and Welsh parliaments "parish councils" (as Blair described them) with puppet leaders, chosen by Blair leading a perpetually Labour led administration.
There should always have been an English parliament and the funding mechanisms should have been changed from Barnett, to tax and spend within the nations, with a Federal parliament, of greatly reduced size, making decisions on matters not devolved. It would have been the perfect time to abandon the anachronistic house of aristocrats and replace it with a senate with elected members form the 4 "countries". Probably 50 members in total would have been all that was required.
I accept of course that the different status of the nations in the late 90s would have presented problems... with Wales not having a legal system of its own, and Northern Ireland being a province, rather than a country, and sharing some of its laws with the Republic. But more work should have been done on this before the flawed legislation was enacted.
After reading Iain's piece I am even more convinced of the need for us to be two, or possibly more, separate nations.