I had a moby with dd(3) but never really got on with it completely - I didn't like the faff.
I've had a look online at the Close ones which look very good. Any experiences? Dd will be either an old 3 or just 4 when baby comes in October and doesn't really use a buggy so I'm not bothering with a double, not for a 4 year old! So dd walking holding my hand, and baby in a sling I think I could cope with!