well there are two main types of cloth nappies, the all in ones, where you have an absorbent bit with a waterproof cover attached. Those you treat almost like a disposable. Wear then wash.
Second are the sort I prefer which, as you described, consist of a waterproof outer 'wrap' and an absorbent inner pad or nappy (depending which style you go for). These ones you just wash the absorbent bit after every wear. The waterproof wrap can be used a few times before it gets whiffy.
If you line dry them then I do think they're probably more ecologically friendly, especially as I used eco egg to wash them, so no detergent. The main thing for us was the saving money though. Nappies are so expensive, but washing them isn't really and if you choose carefully then you can get ones that will even dry indoors on an airer overnight, though March is a good time for a baby as you then have the whole summer ahead of you to deal with the frequent nappy washes!
Does that answer all questions?