@ Den - I haven't seen the DLA forms for a while but the PIP one looks very much the same to me at first glance anyway.
I'm sure Taf will give us his insight once he's filled it out. I'd certainly be interested to know what he thinks. My impression is that the new system is not so much geared towards physical disabilities and that may suit Taf's situation with his twins very well. Fingers crossed he gets a good result!