Anybody has experience with traveling to Lao ( north ) this time of the year? Im thinking of going to Luang Nam Tha. What is the best way to get there? Bus to Mengla and transfer or take bus to KM-LPrabang and get off in Na Toei? Just dont want to get off in some small time in the middle on the night and looking for hotel.

Take the bus from Mengla to Luang Namtha. Goes from bus station. Easy thing, but the smoking ban will not be on that bus in a few years still.

Thanks.
I just couldn't find a climate there. Ive read terrain is 800-2000m mountains and could be cold .

If you go trekking, and upwards, yea. Othervise, nope.

There are direct buses from Jinghong to Luang Namtha at about 7:30AM and about 11AM, 70rmb, travel time, including stop at the border, about 6-6&1/2 hrs. Overcast in Luang Namtha until about noon and a little chilly, then bright sunlight and pleasantly warm for the rest of the day, slightly chilly again after sunset. I'm in Luang Namtha now, have been here 4 days - same weather every day.
At the bus station in Jinghong, the bus you want is for 'Nanta', the Chinese name for the place.
Eat at Bamboo Lounge when you want western food, it is really excellent and they have a sense of social responsibility for training their staff and in paying them, in their trekking connections (called Forest Retreat), and in supporting local schools.

Thanks gus for advice!
Alien: I suppose the weather is like in KM. I guess still need to pack some warm clothes. When I was in Laos last time the prices for hotel were 5-10$, food 1-5$ motorbike 5-7$, visa 25$ fpr EU 30$ CN. I believe that has changed. We r ( with my gf ) going on low backpackers budget so not sure if we can enjoy luxury experience of western food. I also remember that hiking ( tracking or what they call it ) trips were bit exp. 20-30$ per day, and it was about 6h walking in forest to some tribe village. Not much fun ( no scenic views or adventure ) during those 6 hours. So I prefer to rent moto and explore places my self.
Btw. could u recomend something, please?

Take motorbike to Muang Xing and make sure to have a raincoat with you. If u still want to drive when sun getting down, you need something to protect eyes, as millions of small creeps flying around. Motorbike is best thing there anyway.

Dont miss the roasted duck at market.

Lahu villages on mountain tops worth the hike, but to escape the organized cost, you need to find the backdoor, i.e. a local opportunist. But the chances are small for a newbie around.

Thanks Pete for reminding, I already had a chance to experience moskito kinda stuff hitting my face on the way back after sunset:-) I ll be ready this time.
Def.try this roasted duck, cant wait! I'd like to support local tour agency instead some opportunist, but if the price is to high 4 us, we just skip the trip. I can imagine that would be like ZOO think in Myanmar, where tourists come in groups and photographing local people from indiscreet distance.

@Alexez: Weather is NOT like Kunming, at least not at the altitude of Luang Namtha. Sun just came out (11AM Lao time). Unless you're going to some altitude, you only might want to bring a light jacket, and short-sleeved shirts - morning 'chill' I referred to is the sort where some people might just ignore it (maybe 15 degrees) - my statement about 'overcast' - I probably should have just said morning haze. Virtually no rain from now until May, certainly none since I've been here.
Not sure what you'd want me to recommend.

My guesthouse charges me US$7 per day; prices of others, perhaps slightly better, might be $12. Visa now perhaps more like $35. Exchange rate at bank about US$1 = 8000 Lao kip.

Thanks Alien, thats good news! Do they exchange RMB as well or is $ better rate? We are going at 10th. Might do some short hike but nothing extreme coz my gf is KM and She is small, so for her is all double distance :-), if u know what I mean. Im enthusiastic photographer ( www.photodiscovery.eu ), so Im interested in landscapes, old architecture like ruins, temples but also in local people in their natural environment. By recomendation I meant, some nice place aroud which worth to visit, in your opinion. There could be lots of tourist "traps" which I came accross many times on my jorney in asia. As I wrote above example: 6h boring hike in dark forest and slept in some local village which was authentic tribe stuff, but not worth such a long hike. I understand the local people need to make money somehow so I dont blame them. So next time I took moto and randomly went to some villages and on the way passed some scenic points which tour agents didnt consider as something interesting.

Thanks again for your reply!