I've tried MEOS and Tots, and definitely prefer Tots. Have an average sized chubbyish boy though. I have had size 1,2 & 3 though. We didn't use the size 1 up to the max weight - quickly moved on to size 2's. We've been using the size 3's for ages as well, and I still don't think he's 'officially' big enough for them. We've had no problems with leaks in any size.
I only use ME Airflow wraps now (Tots are rubbish). Again, the sizing doesn't seem too important - he can fit in M/L, L and XL at the same time with no leaks.
Definitely prefer the organic ones - nice and soft. I use cloth liners rather than fleece, but it all depends on what suits the baby.
Buying a few of each is a good suggestion - we only had 5 Tots to start with (some Kushies, some Motherease One Size (MEOS), some Motherease multifit (which we still use when we need a slimmer nappy), and a few others , but sold on what didn't agree with us, and upped our Tots collection. The only problem is the addictiveness - I have at least 80 nappies across the three sizes now , but they will easily do the next baby, and still be saleable (the size 1's at least).
I bought a lot of mine second hand - the nappy lady website in particular is full of people who tried cloth, but didn't get on with it for whatever reason, so you can buy almost new (or even brand new sometimes) nappies for a fraction of the new price.