Compiling this list wasn't easy. There's nothing particularly special or particularly bad in Laos.
Many things were great, so narrowing it down was heard, and very little wasn't, so I'm only writing 4 "worse" thing because I had to look for it!

Laos Top 4:

- The atmosphere in Luang Prabang
- Beautiful, nice people that don't hassle you at all, even at night markets.
- Tubbing in Vang Vieng - beautiful scenery.
- Hanging out and feeling the culture in Vientiane.

Laos bottom 4:

- Restaurants and bars close way too early, some of them even before 10PM, even on touristy areas.
- Agencies staff are edgy and not all that helpful. Much like their neighbours in Vietnam some can lie to get your money as well.
- Not being able to take more than $70 per day on ATMs.
- Can't think of anything else. Loved Laos! I'll modify if I remember anything.
 
http://marjorielopes.blogspot.com/2009/01/best-and-worse-of-laos.html