How well do you rate the Royce disc hubs? What are the freewheel mechanisms like, how many engagement points? pawls? ease of servicing ? Noise level?
The Royce hubs are as good as they come. Bearings run smoother than any hub I've ever tried, you wouldn't think that one bearing would feel different to any other when they're new, but Royce ones do. We actually just had someone this morning email to say how great their Royce hubs had been after 6 months heavy use, Royce made him a special axle too. They are a good company to deal with. There are lighter hubs but their 365g isn't overly heavy and it's more than made up for with their strength and reliability. Plus the hubs just have that extra special feel about them that you don't get with most others. I expect the wheel would come in at 806g, but would feel lighter. Extra weight on the hub doesn't make a lot of difference. Everything is available immediately (the hub to order, but in stock at Royce), so up to 2 weeks delivery time, no longer.
I don't have any information on the specifics of servicing the Royce hubs but if you needed to maintain them it would be a pretty standard procedure of removing end caps / axle to access the freehub and get into the bearings. It should be a pretty rare occurrence though. If you need to grease the pawls (which is normally the only servicing you would need to do) they make a grease injection kit: http://www.genisysconsulting.co.uk/royce-uk/new%20products.htm (that link may not work soon as they are just putting up a new website). I just phoned Royce to find out about the pawls on the disk hubs (the spec varies across the different hubs in the range). They use 3 pawls with 21 engagement points. I can't remember how noisy they are. Not as loud as Hopes anyway.