glitter, I really doubt that using the dryer would cancel the environmental benefits. It would REDUCE it, certainly, but disposables are massively environmentally destructive.
Reusables are lower impact in terms of manufacture (using non-organic cotton/bamboo, while not marvellous, is still better than using our very limited oil reserves). They are not dumped in landfill, with, aside from the pollution and so forth, the emissions resulting from transporting the nappies to said landfill. You also do not have the carbon emissions resulting from repeated transport of raw materials to the factory, transport of the nappies to the shop, and then to your home.
So yes the environmental gold star approach is to dry them on a clothes horse.
But if your choice is between disposables (even "nice" ones like moltex or tushies), I would not choose disposables for enviormental reasons.
(I would, however, not criticise anyone for choosing disposables for CONVENIENCE. I don't think they ARE more conveniant but that is only something I can say of me, in my circumstances IYKWIM)
How does your dp (if you have one) feel about this all btw? Dp has always done most of the nappy washes, especially in the early days-I doubt very much I'd have managed to stick with cloth if I'd had to sort out the nappies...