I was so pleased with the result of cleaning my Alpkit Pipedream 400 sleeping bag, that I decided to send my modified Rab Neutrino SL 200 to Elite Cleaning. Cleaning definitely improves the loft. It is even noticeable in a bag like the Neutrino that hasn’t been used that much. The down is more fluffy and better distributed in the baffles.
I also like the idea that it receives a wash-in proofer. Not only does it mean the shell has a measure of water resistance, but the down should also be less vulnerable to absorbing water. I suspect that the water resistance won’t be at the same level as the specially treated down that is now being used in sleeping bags and jackets. Nonetheless, it is likely to better than untreated down.
If you’ve got down gear, it’s definitely worth considering professional cleaning. I will be sending my summer bag (WM Highlite) for cleaning soon. I want to emphasise, I have no links with Elite, other than being a satisfied customer and there are other companies that do professional cleaning, like Mountaineering Designs.