Thanks both. In a different situation I would completely take these views on board, would want the gold-plated option and would probably give the same advice to others. However, unless I hear some absolute horror stories relevant to my circumstances here or elsewhere, I'm likely to go ahead with the low-cost option.
There is actually only one clause in the consent order that I'd ever bother getting enforced through the courts and that's the one saying that he can make no future claim against me. (I don't believe he would but life can be unpredictable.) I've been led to understand that the language for this is usually pretty standard?
ExH has an alcohol problem, no savings and a tiny pension he hasn't paid into for years. I am the higher earner, have had a pension since my early twenties and have no interest in receiving spousal maintenance or any part of his pension. The marriage was less than 10 years.
The family home is in my name and Ex does not want to claim anything from it as he accepts that I saved the deposit, took out the mortgage and paid it every month while he contributed nothing at any stage (I am an idiot). Unfortunately, his tens of thousands of pounds of debt are also in my name since he was unable to get credit (won't make that mistake again either). Neither of us has any other significant assets.
Yes, we have agreed on a level of child support in line with his current salary with annual reviews for inflation or change of circumstance on either side. Any future disputes about child support would have to go through the CSA after a year anyway, I think.
We have agreed that any future bonuses or cash gifts received by him are to be split 50/50 between us until such time as the debts above are paid off etc..
In summary, exH has nothing except a monthly salary. He's chaotic and financially irresponsible and my expectations of him are low regardless of his intentions. In the event of him breaking the terms of the Consent Order, nothing would be worth the expense and effort of enforcing other than the clause that he will not claim against me in future.
I don't have much spare cash. On paper my salary is too good to qualify for any help with legal costs but childcare, mortgage and commuting mean that I don't actually have anything left over at the end of the month to pay the ~£800 it seems to cost to get a consent order from a local law firm. I'm in line for small bonus at work this month (a couple of hundred) and will be using this to get the Consent Order done online.