I tend to steer away from the first batch of a new product (like the Cobalt wheels).

 They might be amazing, but I'd prefer to wait a while until plenty of people have tried and tested them before shelling out money on them. 

 Look what happened with Spesh's first run of their in-house forks on the new Enduros.

 They were a bag of wank

Crossmax SLs are fantastic wheels but they need TLC. Fulcrums seem like excellent wheels from what I've heard although I've never tried a set myself.  Don't go near Spinergys - I thought they'd disappeared of the face of the Earth so I can't imagine spares being that easy to get hold of. 

 I just bought myself some light and strong wheels - Burgtec hubs laced on to DT rims - Chain Reaction - £435. 

Or.......And these are by far the trickest wheels in the world:

Industry Nine

industry 9, a king build, or a tune build.

had a spin on a set of tune hubbed wheels a couple of weeks ago, felt really lovely. lights as buggery too (with stans olympic and uber light tyres).

my king ft wheel is holding up well, weighs little, looks good, but needs a bit more TLC than their h/sets.

i'd go custom, as opposed to factory. 

The only problem with the Hopes is, because they're relatively good value, the world and his wife will have them.

 Not an issue if you don't care about things like that obviously. But if you want something with that little 'something' extra, go for something else. 

 Haven't had a spin on i9 wheels so couldn't comment on whether the weight saving on the ultralights is worth it or not. I would have thought they wouldn't be quite as stiff as the All Mountain, plus the spokes are a little thinner so don't look quite so trick

"The only problem with the Hopes is, because they're relatively good value, the world and his wife will have them. "

not many people have the XC 3s or the pro111 SP..

The Cobalts are lovely to ride. Nice and light, I got no noticable deflection through them and the engagement from the rear hub was nice and snappy. I'm not light (I make no secret of this) and gave them a good hoofing on the new Blur LT and they behaved brilliantly. Not cheap ( I heard about £700 in the UK) but really nice wheels.

I've got Chris King hubs on everything and wouldn't swap from them now. Only thing I've changed for the set on the new bike is have them built up with the Stans Olympic rims and DT Revolution spokes to save even more weight.

I've seen too many problems with the Mavic sets. Spokes are still a problem to replace and a lot more expensive than spokes should be.

The Rovals are very nice wheels and PLENTY light enough and would save you some money to buy a great set of tyres (I think Mike got his for around £400 but I'll let him confirm or deny that) and a tubeless kit.

Avoid the Spinergy wheels. They ride like a damp sponge and just take all the fun out of riding a bike. Far too insulating and they flex like paper plates.

I have the Fulcrum RM1 if that's any use. I've had em for about 2-3 months and am happy as a pig in pig poo with em.

They're on my 5. Maintenance/bearing adjustment on these wheels looks piss easy and the sealing seems fairly good. Will be interesting to see how they cope with their first full winter. From what I've seen of the inards I'd say they're goona be as easy to look after as me pro2's only lighter/stiffer and much better rolling.

The RM0's would be the jack russells brussels if the RM1's are anyhting to go by.