I haven't used either of those nappies, but when i was looking into nappies I had a good look at both. I thought the mothercare nappys sounded like a great idea but when I opened up the pack I didn't like the feel of the wrap and didn't like the fact that so much of the plastic-y feeling wrap would be touching lo's skin. The bambino mio's seemed a bit less icky but i still didn't like the idea of too much plastic-y bits on lo's skin.
What I ended up doing was buying a whole bunch of different nappies off ebay - just looking for bargains so I had plenty to try out in size 1's. For size 2's I've settled on little lamb bamboo or microfluffles, although if I find any tots bots bamboo bargains on ebay then I'd use them too.
I'm not so keen on the birth to potty nappies (sold mine on ebay without even using them!) as they seemed so big on small babies - yes I know they are adjustable but they were just so bulky!
Personally I'd reccomend contacting your local council to see if they provide a grant towards reusables (i got £45 off mine) and seeing if they provide a list of local nappy suppliers/councillers (the ones on my list all seemed to be work at home mums) who can talk you through the various types of nappies and give demonstrations, and probably information on how to hire trial packs if that suits you. If it wasn't for the nappy lady I talked to I wouldn't have known that bamboo nappies are good and absorbant for heavy wetters. I think its definately worth trying a few different types then you'll know what suits you and your lo - so many people have their own favourite that works for them and reusables can be baffling to get into!