Not really. I like my Alpkit bag, it's cheap, no-frills, not hugely breathable. This Rab model has an eVent upper, bathtub floor, full zip closure, midge net and has a guy line thing to suspend it off your face. The Rab is a lot bigger inside than the Alpkit, could easily fit a huge winter bag + inflatable mat in there.
If you want racing weight, then companies do superlight, super compact pertex bags, but they will wet through and are relatively delicate. I'll take the Alpkit if I'm going for a cheeky overnight in the summer or big audax-type events as a just-in-case. If I'm going for a week in Scotland during midge-season, or out in the Peak during the colder/wetter months I'll happily put up with the bulk/price for more breathability and no bloody bugs.