Give it a go @Twiggyjumps. What have you got to lose? Why does everyone assume feet, or ankles, will hurt more? Old wives tale, in my opinion. And it is just my opinion.
The killer question is 'Where do you find a vein on a baby?' Feet. I just don't think most nurses are trained to consider it. I had one refuse because 'Feet are dirty' Well, that's what antiseptic wash is for, besides, I can't remember the last time I wiped my arse with my toes.
I do think it is something to consider. I, personally, have always found my hands and arms more sensitive. I've never had a drip fail in my feet--once again there have been some 'robust' discussions with anaesthetists before surgery. I win those because I know my body best and I've been there every time I've needed IV access.