I need to choose a great stem for my XC bike and new carbon riser. Easton? (EA50, EA70 or MG60)The new FSA? How about a Raceface? And is the Thomson Elite really that good? Who sells the thomson?

all of the ones you mentione are supposed to be the mut's nuts. Personally I love the look of the Thompson: no welds at all. That's the bad boy I would be spending my hard-earneds on

Using a Easton EA50, 100mm and 10 degree rise. Great wee stem, good looking too. No idea about the rest thou...

I have Monkeylights fitted to a RF Deus. The 4 clamp bolts take hardly any pressure before they lock the bars solid. It's not a superlight stem, but it has no welds and is incredibly stiff.

Not got a monkeylite but got an RF Deus stem and its brilliant. It looks the business and like Chris says is very stiff and for its strength is quite light.

IIRC the monkeylite has a reinforced stem area anyway so most stems should be fine for it just make sure there are no sharp edges or burrs. Obviously don't over tighten but scratching the bar is the biggest thing to worry about I think as that sets up weak points where the bar can then be liable to crack.

the key problem with clamping carbon bars into a stem is that any burs (poor quality finish etc..) can cause deformation of the bars which cause stress risers and therefore weaken the bars.... (as Matthew said)

so as long as it's a quality stem you should be fine....

personally I use a RF Deus with a RF Air Alloy XC as Im a tad on the punishing side with my bike and dont fancy snapping carbon bars (mainly cause I cant justify the cost of the Monkeylites....)

you'll obviuosly not want to scratch the bars when fitting the shifters brake levers etc...

Have you considered a Pace XC stem they're absolutely gorgeous. I've just looked on the pace-racing.co.uk website however and unless i'm mistaken it seems to have gone from the range. It was on the old pace website a couple of months ago. Nicest looking stem there is.

I'm another with RF Deus and Monkeylites,absolutely no problems after 4 months