So you're currently trying a ring sling? What position do you have the babe in? I could never get my DS comfortable in a cradle hold, but he did really well in a tummy to tummy hold, similar to what he was used to in the Moby.
There's nothing that says that during the day when you're home (alone?), you can't just wear the Moby, whether she's in it or not. I know any number of mamas (myself included) who did this. No shirt, no bra, just a Moby, and if necessary a cardigan sweater over that for my arms. That way you can pop her in and out when necessary and not be constantly retying it.
However, soon enough she will start outgrowing the Moby (my guy was about 3 mos), and you will definitely need another option. The Ergo is widely popular, but if your DH is large, it's not always the best option - many large people find it uncomfortable (even with the belt extender) because the shoulder straps land in the wrong place. If you really like the Moby, you can go with a woven wrap, which is the most versatile option, but it does have a learning curve, and has the same problem as the Moby - it's not a quick or easy on/off. For that, the RS would be my first choice (pouches are sized, so what would work for you wouldn't work for your DH). I also have a MT and an Ombuhimo - the Ombu is by far my favorite carrier once we outgrew the Moby, but IMO it's best use is for back carries, and it's great for a toddler - one that's not steady enough to walk but still is interested and wants to be involved in everything.
I've never been terribly fond of my MT - it works well, but it's just not the wonderful great thing everyone led me to believe it was. It's fiddly and a bit of a pain. That being said, now that DS is 40 lbs, it's the only carrier I can use with him, since it puts his weight on my hips and not my shoulders/back. I got a custom MT so that it was sized correctly to me (since DH and I are both large), and I got one with a padded waist and a waist buckle instead of straps to tie (the shoulders still tie - it's called a half-buckle tai). That way it's as comfortable as possible, and as versatile as possible. My sitter has used it and she's a tiny little thing, my DH has used it, and he's a foot taller than me, and I use it. For fitting a range of body types/sizes it works well. It's quicker off/on than a Moby, but not as quick as a RS.