IPSA has cost the taxpayer well over £6 million, has consumed well over half a million pounds in lawyers' fees and spin doctors, and does a nice line in furniture. It wasn't needed in the first place (the Fees Office was in good order once it had been purged and had its rules tightened following the expenses scandal), and it should certainly be scrapped now. The costs of MPs' expenses could be brought down further were a flat-rate allowance brought in, as Adam Afriyie suggested and has argued on this site.
I suspect that mine is a minority view, and that the majority are all for IPSA. That's all fine and dandy. But in which case, it is hoist by its own petard when IPSA proposes a pay rise for MPs. Not so long ago, MPs voted on their own pay, and could thus be lobbied by constituents not to back an increase. But under the IPSA regime, that's no longer possible. If IPSA decides to award MPs a pay rise, they have no power to vote to stop it (without first changing the revelant legislation, of course). If you like IPSA, you must lump it – at least as far as MPs pay is concerned.