My child seats (from over 20 years ago) were always the cheaper end of the scale but solid and they gave me no problems either. I am not sure I would have wanted something that tilted though, my kids would always sleep anywhere (including on the pillion of a motorbike on a couple of occasions, in movement!) and, being always at the large end, keeping the weight forward rather than back was always the objective for stability.
I think that has all answered any queries I might have had so thank you all for the input, very useful
Cheers Jo