Love, love, love this place. I wish we discovered it sooner. Now every time we go back to Vegas (usually 3x/yr) we have to make time to visit Sweets Raku.
Lunch will usually take about three hours (watching them make it + eating the yummy goodness!) so make sure you have time. This does not include the wait time if you go after opening time. Super neat experience. I can't wait to take friends here.
Very clean, small portions but filling, pricey for what you're getting, elegant/pretty and the employees are very nice. Some stuff were just okay (i.e. mango sorbet), some are awesome (i.e. salmon croissant), but overall, you go for the experience of watching them make the pretty food.
Make sure you try everything! I highly recommend the prix fixe menu.
UPDATE: No more edible menu. A lot of stuff are premade and they just assemble it anywhere on the counter (usually towards the kitchen), no longer making it specifically in front of you. It'll still take them about 1.5 - 2 hours to make you your food b/c they're making other people's food and you're just waiting. It's still very pretty desserts for the most part. Try the Mars dessert. They light it on fire.