Vientiane Palace is great as a lunch location (it'd probably be good for dinner as well). Portions are fairly large. The spiciness is something you can ask to specify with many dishes. While I've one one or two occasions had something that turned out more mundane than I expected, usually the food is excellent. I concur with Sarah that the service isn't bad, just "business-like", although I confess I've never eaten here with a guest, just by myself. Which doesn't mean anything, since the food's good enough that I'd recommend to anyone who generally likes Southeast Asian cuisine and wants to try something new.