for us personally the babasling was handy when bub wanted to b close n I needed to get things done. As pp mentioned its tad straining on the shoulder on long uses but good for short trips.
we love the Ergo but its hard to sit when strapped due to the waist padding. its balances the weight pretty well and we take bub to the footy in an Ergo as it keeps him warm too. Nowadays I put bub in a meitai on my back if I need housework done as I get more mobility this way, bending to hang washing & dishes etc
Feeding wise I've done it in both the babasling n Ergo. One the bub lies sideways, the other they koala hug u n feed.
That's how we've done things anyways. Hth