I haven't read all the messages, so forgive me if I repeat something.
We started using washable nappies after our son was about 2 weeks old and the poo had somewhat stabilised. I tried a few different brands, and had also made some of my own (with a free pattern off the internet - before the baby was born and I still had time to sew). We decided that the best fitting, and best poo-containing ones were Tot Bots. I like the old-style cover that has a gusset, but Tot Bots stopped making these mid-baby, so I sewed some more myself using PUL fabric.
Now TotBots have changed their nappies again, and use bamboo fabric and a polyester outer (which still takes a cover) and it is slimmer than the bulky cotton terry nappies. We like the new ones, called Flexitots, but we used the old style too.
Just now we're trying Little Lambs, and we like them as well. It is a kind of bulky nappy made out of bamboo terry, and I really like their covers because they have a bit of give to them, unlike the TotBots. So I often use a Little Lamb size 2 cover with a TotBots size 2 nappy.
If I had known then what I know now, I wouldn't have bothered to buy that many size 1 nappies, because my son was 4.3kg at birth and didn't wear them very long before he outgrew them. However, it's easy to say that now looking back, and well, we're all set for Child Number Two.
As you say, it's easier to start out with washable nappies if you don't know the difference and carry on, than to switch. I'm the youngest of 7 and in those days, everyone used the fabric nappies with big safety pins, so the shaped nappies are much easier than what we had in the old days!